Hybrid maize plant and seed 31G66

ABSTRACT

According to the invention, there is provided a hybrid maize plant, designated as 31G66, produced by crossing two Pioneer Hi-Bred International, Inc. proprietary inbred maize lines. This invention relates to the hybrid seed 31G66, the hybrid plant produced from the seed, and variants, mutants, and trivial modifications of hybrid 31G66. This invention also relates to methods for producing a maize plant containing in its genetic material one or more transgenes and to the transgenic maize plants produced by those methods. This invention further relates to methods for producing maize lines derived from hybrid maize line 31G66 and to the maize lines derived by the use of those methods.

FIELD OF THE INVENTION

This invention is in the field of maize breeding, specifically relatingto hybrid maize designated 31G66.

BACKGROUND OF THE INVENTION Plant Breeding

The goal of plant breeding is to combine in a single variety or hybridvarious desirable traits. For field crops, these traits may includeresistance to diseases and insects, tolerance to heat and drought,reducing the time to crop maturity, greater yield, and better agronomicquality. With mechanical harvesting of many crops, uniformity of plantcharacteristics such as germination and stand establishment, growthrate, maturity, and plant and ear height is important.

Field crops are bred through techniques that take advantage of theplant's method of pollination. A plant is self-pollinated if pollen fromone flower is transferred to the same or another flower of the sameplant. A plant is sib pollinated when individuals within the same familyor line are used for pollination. A plant is cross-pollinated if thepollen comes from a flower on a different plant from a different familyor line. The term “cross pollination” and “out-cross” as used herein donot include self pollination or sib pollination.

Plants that have been self-pollinated and selected for type for manygenerations become homozygous at almost all gene loci and produce auniform population of true breeding progeny. A cross between twodifferent homozygous lines produces a uniform population of hybridplants that may be heterozygous for many gene loci. A cross of twoplants each heterozygous at a number of gene loci will produce apopulation of heterogeneous plants that differ genetically and will notbe uniform.

Maize (Zea mays L.), often referred to as corn in the United States, canbe bred by both self-pollination and cross-pollination techniques. Maizehas separate male and female flowers on the same plant, located on thetassel and the ear, respectively. Natural pollination occurs in maizewhen wind blows pollen from the tassels to the silks that protrude fromthe tops of the ears.

The development of a hybrid maize variety in a maize plant breedingprogram involves three steps: (1) the selection of plants from variousgermplasm pools for initial breeding crosses; (2) the selfing of theselected plants from the breeding crosses for several generations toproduce a series of inbred lines, which, individually breed true and arehighly uniform; and (3) crossing a selected inbred line with anunrelated inbred line to produce the hybrid progeny (F1). After asufficient amount of inbreeding successive filial generations willmerely serve to increase seed of the developed inbred. Preferably, aninbred line should comprise homozygous alleles at about 95% or more ofits loci.

During the inbreeding process in maize, the vigor of the linesdecreases. Vigor is restored when two different inbred lines are crossedto produce the hybrid progeny (F1). An important consequence of thehomozygosity and homogeneity of the inbred lines is that the hybridcreated by crossing a defined pair of inbreds will always be the same.Once the inbreds that create a superior hybrid have been identified, acontinual supply of the hybrid seed can be produced using these inbredparents and the hybrid corn plants can then be generated from thishybrid seed supply.

Large scale commercial maize hybrid production, as it is practicedtoday, requires the use of some form of male sterility system whichcontrols or inactivates male fertility. A reliable method of controllingmale fertility in plants also offers the opportunity for improved plantbreeding. This is especially true for development of maize hybrids,which relies upon some sort of male sterility system. There are severalways in which a maize plant can be manipulated so that is male sterile.These include use of manual or mechanical emasculation (or detasseling),cytoplasmic genetic male sterility, nuclear genetic male sterility,gametocides and the like.

Hybrid maize seed is often produced by a male sterility systemincorporating manual or mechanical detasseling. Alternate strips of twoinbred varieties of maize are planted in a field, and the pollen-bearingtassels are removed from one of the inbreds (female) prior to pollenshed. Providing that there is sufficient isolation from sources offoreign maize pollen, the ears of the detasseled inbred will befertilized only from the other inbred (male), and the resulting seed istherefore hybrid and will form hybrid plants.

The laborious detasseling process can be avoided by using cytoplasmicmale-sterile (CMS) inbreds. Plants of a CMS inbred are male sterile as aresult of factors resulting from the cytoplasmic, as opposed to thenuclear, genome. Thus, this characteristic is inherited exclusivelythrough the female parent in maize plants, since only the femaleprovides cytoplasm to the fertilized seed. CMS plants are fertilizedwith pollen from another inbred that is not male-sterile. Pollen fromthe second inbred may or may not contribute genes that make the hybridplants male-fertile. The same hybrid seed, a portion produced fromdetasseled fertile maize and a portion produced using the CMS system canbe blended to insure that adequate pollen loads are available forfertilization when the hybrid plants are grown.

There are several methods of conferring genetic male sterilityavailable, such as multiple mutant genes at separate locations withinthe genome that confer male sterility, as disclosed in U.S. Pat. Nos.4,654,465 and 4,727,219 to Brar et al. and chromosomal translocations asdescribed by Patterson in U.S. Pat. Nos. 3,861,709 and 3,710,511. Theseand all patents referred to are incorporated by reference. In additionto these methods, Albertsen et al., of Pioneer Hi-Bred, U.S. Pat. No.5,432,068, have developed a system of nuclear male sterility whichincludes: identifying a gene which is critical to male fertility;silencing this native gene which is critical to male fertility; removingthe native promoter from the essential male fertility gene and replacingit with an inducible promoter; inserting this genetically engineeredgene back into the plant; and thus creating a plant that is male sterilebecause the inducible promoter is not “on” resulting in the malefertility gene not being transcribed. Fertility is restored by inducing,or turning “on”, the promoter, which in turn allows the gene thatconfers male fertility to be transcribed.

There are many other methods of conferring genetic male sterility in theart, each with its own benefits and drawbacks. These methods use avariety of approaches such as delivering into the plant a gene encodinga cytotoxic substance associated with a male tissue specific promoter oran antisense system in which a gene critical to fertility is identifiedand an antisense to that gene is inserted in the plant (see:Fabinjanski, et al., EPO 89/3010153.8 Publication No. 329,308 and PCTApplication PCT/CA90/00037 published as WO 90/08828).

Another system useful in controlling male sterility makes use ofgametocides. Gametocides are not a genetic system, but rather a topicalapplication of chemicals. These chemicals affect cells that are criticalto male fertility. The application of these chemicals affects fertilityin the plants only for the growing season in which the gametocide isapplied (see Carlson, Glenn R., U.S. Pat. No. 4,936,904). Application ofthe gametocide, timing of the application and genotype specificity oftenlimit the usefulness of the approach and it is not appropriate in allsituations.

The use of male sterile inbreds is but one factor in the production ofmaize hybrids. The development of maize hybrids in a maize plantbreeding program requires, in general, the development of homozygousinbred lines, the crossing of these lines, and the evaluation of thecrosses. Maize plant breeding programs combine the genetic backgroundsfrom two or more inbred lines or various other germplasm sources intobreeding populations from which new inbred lines are developed byselfing and selection of desired phenotypes. Hybrids also can be used asa source of plant breeding material or as source populations from whichto develop or derive new maize lines. Plant breeding techniques known inthe art and used in a maize plant breeding program include, but are notlimited to, recurrent selection, backcrossing, double haploids, pedigreebreeding, restriction fragment length polymorphism enhanced selection,genetic marker enhanced selection, and transformation. Often acombination of these techniques are used. The inbred lines derived fromhybrids can be developed using plant breeding techniques as describedabove. New inbreds are crossed with other inbred lines and the hybridsfrom these crosses are evaluated to determine which of those havecommercial potential.

Backcrossing can be used to improve inbred lines and a hybrid which ismade using those inbreds. Backcrossing can be used to transfer aspecific desirable trait from one line, the donor parent, to an inbredcalled the recurrent parent which has overall good agronomiccharacteristics yet that lacks the desirable trait. This transfer of thedesirable trait into an inbred with overall good agronomiccharacteristics can be accomplished by first crossing a recurrent parentto a donor parent (non-recurrent parent). The progeny of this cross isthen mated back to the recurrent parent followed by selection in theresultant progeny for the desired trait to be transferred from thenon-recurrent parent. Typically after four or more backcross generationswith selection for the desired trait, the progeny will containessentially all genes of the recurrent parent except for the genescontrolling the desired trait. But the number of backcross generationscan be less if molecular markers are used during the selection or elitegermplasm is used as the donor parent. The last backcross generation isthen selfed to give pure breeding progeny for the gene(s) beingtransferred.

Backcrossing can also be used in conjunction with pedigree breeding todevelop new inbred lines. For example, an F1 can be created that isbackcrossed to one of its parent lines to create a BC1. Progeny areselfed and selected so that the newly developed inbred has many of theattributes of the recurrent parent and some of the desired attributes ofthe non-recurrent parent.

Recurrent selection is a method used in a plant breeding program toimprove a population of plants. The method entails individual plantscross pollinating with each other to form progeny which are then grown.The superior progeny are then selected by any number of methods, whichinclude individual plant, half sib progeny, full sib progeny, selfedprogeny and topcrossing. The selected progeny are cross pollinated witheach other to form progeny for another population. This population isplanted and again superior plants are selected to cross pollinate witheach other. Recurrent selection is a cyclical process and therefore canbe repeated as many times as desired. The objective of recurrentselection is to improve the traits of a population. The improvedpopulation can then be used as a source of breeding material to obtaininbred lines to be used in hybrids or used as parents for a syntheticcultivar. A synthetic cultivar is the resultant progeny formed by theintercrossing of several selected inbreds. Mass selection is a usefultechnique when used in conjunction with molecular marker enhancedselection.

Molecular markers including techniques such as Isozyme Electrophoresis,Restriction Fragment Length Polymorphisms (RFLPs), Randomly AmplifiedPolymorphic DNAs (RAPDs), Arbitrarily Primed Polymerase Chain Reaction(AP-PCR), DNA Amplification Fingerprinting (DAF), Sequence CharacterizedAmplified Regions (SCARs), Amplified Fragment Length Polymorphisms(AFLPs), Single Nucleotide Polymorphisms (SNPs) and Simple SequenceRepeats (SSRs) may be used in plant breeding methods. One use ofmolecular markers is Quantitative Trait Loci (QTL) mapping. QTL mappingis the use of markers, which are closely linked to alleles that havemeasurable effects on a quantitative trait. Selection in the breedingprocess is based upon the accumulation of markers linked to the positiveeffecting alleles and/or the elimination of the markers linked to thenegative effecting alleles from the plant's genome.

Molecular markers can also be used during the breeding process for theselection of qualitative traits. For example, markers closely linked toalleles or markers containing sequences within the actual alleles ofinterest can be used to select plants that contain the alleles ofinterest during a backcrossing breeding program. The markers can also beused to select for the genome of the recurrent parent and against themarkers of the donor parent. Using this procedure can minimize theamount of genome from the donor parent that remains in the selectedplants. It can also be used to reduce the number of crosses back to therecurrent parent needed in a backcrossing program. The use of molecularmarkers in the selection process is often called Genetic Marker EnhancedSelection.

The production of double haploids can also be used for the developmentof inbreds in a breeding program. Double haploids are produced by thedoubling of a set of chromosomes (1N) from a heterozygous plant toproduce a completely homozygous individual. For example, see Wan et al.,“Efficient Production of Doubled Haploid Plants Through ColchicineTreatment of Anther-Derived Maize Callus”, Theoretical and AppliedGenetics, 77:889-892, 1989. This can be advantageous because the processcan eliminate the generations of selfing needed to obtain a homozygousplant from a heterozygous source.

Hybrid seed production requires elimination or inactivation of pollenproduced by the female parent. Incomplete removal or inactivation of thepollen provides the potential for self-pollination. This inadvertentlyself-pollinated seed may be unintentionally harvested and packaged withhybrid seed. Also, because the male parent is grown next to the femaleparent in the field there is the very low probability that the maleselfed seed could be unintentionally harvested and packaged with thehybrid seed. Once the seed from the hybrid bag is planted, it ispossible to identify and select these self-pollinated plants. Theseself-pollinated plants will be genetically equivalent to one of theinbred lines used to produce the hybrid. Though the possibility ofinbreds being included hybrid seed bags exists, the occurrence is verylow because much care is taken to avoid such inclusions. It is worthnoting that hybrid seed is sold to growers for the production of grainand forage and not for breeding or seed production.

By an individual skilled in plant breeding, these inbred plantsunintentionally included in commercial hybrid seed can be identified andselected due to their decreased vigor when compared to the hybrid.Inbreds are identified by their less vigorous appearance for vegetativeand/or reproductive characteristics, including shorter plant height,small ear size, ear and kernel shape, cob color, or othercharacteristics.

Identification of these self-pollinated lines can also be accomplishedthrough molecular marker analyses. See, “The Identification of FemaleSelfs in Hybrid Maize: A Comparison Using Electrophoresis andMorphology”, Smith, J. S. C. and Wych, R. D., Seed Science andTechnology 14, pp. 1-8 (1995), the disclosure of which is expresslyincorporated herein by reference. Through these technologies, thehomozygosity of the self pollinated line can be verified by analyzingallelic composition at various loci along the genome. Those methodsallow for rapid identification of the invention disclosed herein. Seealso, “Identification of Atypical Plants in Hybrid Maize Seed byPostcontrol and Electrophoresis” Sarca, V. et al., Probleme de GeneticaTeoritica si Aplicata Vol. 20 (1) pp. 29-42.

Another form of commercial hybrid production involves the use of amixture of male sterile hybrid seed and male pollinator seed. Whenplanted, the resulting male sterile hybrid plants are pollinated by thepollinator plants. This method is primarily used to produce grain withenhanced quality grain traits, such as high oil, because desired qualitygrain traits expressed in the pollinator will also be expressed in thegrain produced on the male sterile hybrid plant. In this method thedesired quality grain trait does not have to be incorporated by lengthyprocedures such as recurrent backcross selection into an inbred parentline. One use of this method is described in U.S. Pat. Nos. 5,704,160and 5,706,603.

There are many important factors to be considered in the art of plantbreeding, such as the ability to recognize important morphological andphysiological characteristics, the ability to design evaluationtechniques for genotypic and phenotypic traits of interest, and theability to search out and exploit the genes for the desired traits innew or improved combinations.

The objective of commercial maize hybrid line development resulting froma maize plant breeding program is to develop new inbred lines to producehybrids that combine to produce high grain yields and superior agronomicperformance. One of the primary traits breeders seek is yield. However,many other major agronomic traits are of importance in hybridcombination and have an impact on yield or otherwise provide superiorperformance in hybrid combinations. Such traits include percent grainmoisture at harvest, relative maturity, resistance to stalk breakage,resistance to root lodging, grain quality, and disease and insectresistance. In addition, the lines per se must have acceptableperformance for parental traits such as seed yields, kernel sizes,pollen production, all of which affect ability to provide parental linesin sufficient quantity and quality for hybridization. These traits havebeen shown to be under genetic control and many if not all of the traitsare affected by multiple genes.

Pedigree Breeding

The pedigree method of breeding is the mostly widely used methodologyfor new hybrid line development.

In general terms this procedure consists of crossing two inbred lines toproduce the non-segregating F1 generation, and self pollination of theF1 generation to produce the F2 generation that segregates for allfactors for which the inbred parents differ. An example of this processis set forth below. Variations of this generalized pedigree method areused, but all these variations produce a segregating generation whichcontains a range of variation for the traits of interest.

EXAMPLE 1 Hypothetical Example of Pedigree Breeding Program

Consider a cross between two inbred lines that differ for alleles at sixloci. The parental genotypes are:

Parent 1 A b C d e F/A b C d e F Parent 2 a B c D E f/a B c D E fthe F1 from a cross between these two parents is:

F1 A b C d e F/a B c D E fSelfing F1 will produce an F2 generation including the followinggenotypes:

A B c D E f/a b C d e F A B c D e f/a b C d E F A B c D e f/a b C d e F

The number of genotypes in the F2 is 3⁶ for six segregating loci (729)and will produce (2⁶)−2 possible new inbreds, (62 for six segregatingloci).

Each inbred parent which is used in breeding crosses represents a uniquecombination of genes, and the combined effects of the genes define theperformance of the inbred and its performance in hybrid combination.There is published evidence (Smith, O. S., J. S. C. Smith, S. L. Bowen,R. A. Tenborg and S. J. Wall, TAG 80:833-840 (1990)) that each of thelines are different and can be uniquely identified on the basis ofgenetically-controlled molecular markers.

It has been shown (Hallauer, Arnel R. and Miranda, J. B., QuantitativeGenetics in Maize Breeding, Iowa State University Press, Ames, Iowa,1981) that most traits of economic value in maize are under the geneticcontrol of multiple genetic loci, and that there are a large number ofunique combinations of these genes present in elite maize germplasm. Ifnot, genetic progress using elite inbred lines would no longer bepossible. Studies by Duvick and Russell (Duvick, D. N., Maydica37:69-79, (1992); Russell, W. A., Maydica XXIX:375-390 (1983)) haveshown that over the last 50 years the rate of genetic progress incommercial hybrids has been between one and two percent per year.

The number of genes affecting the trait of primary economic importancein maize, grain yield, has been estimated to be in the range of 10-1000.Inbred lines which are used as parents for breeding crosses differ inthe number and combination of these genes. These factors make the plantbreeder's task more difficult. Compounding this is evidence that no oneline contains the favorable allele at all loci, and that differentalleles have different economic values depending on the geneticbackground and field environment in which the hybrid is grown. Fiftyyears of breeding experience suggests that there are many genesaffecting grain yield and each of these has a relatively small effect onthis trait. The effects are small compared to breeders' ability tomeasure grain yield differences in evaluation trials. Therefore, theparents of the breeding cross must differ at several of these loci sothat the genetic differences in the progeny will be large enough thatbreeders can develop a line that increases the economic worth of itshybrids over that of hybrids made with either parent.

If the number of loci segregating in a cross between two inbred lines isn, the number of unique genotypes in the F2 generation is 3^(n) and thenumber of unique inbred lines from this cross is {(2^(n))−2}. Only avery limited number of these combinations is commercially useful.

By way of example, if it is assumed that the number of segregating lociin F2 is somewhere between 20 and 50, and that each parent is fixed forhalf the favorable alleles, it is then possible to calculate theapproximate probabilities of finding an inbred that has the favorableallele at {(n/2)+m} loci, where n/2 is the number of favorable allelesin each of the parents and m is the number of additional favorablealleles in the new inbred. See Example 2 below. The number m is assumedto be greater than three because each allele has so small an effect thatevaluation techniques are not sensitive enough to detect differences dueto three or less favorable alleles. The probabilities in Example 2 areon the order of 10⁻⁵ or smaller and they are the probabilities that atleast one genotype with (n/2)=m favorable alleles will exist.

To put this in perspective, the number of plants grown on 60 millionacres (approximate United States corn acreage) at 25,000 plants/acre is1.5×10¹².

EXAMPLE 2 Probability of Finding an Inbred with M of N Favorable Alleles

Assume each parent has n/2 of the favorable alleles and only ½ of thecombinations of loci are economically useful.

No. of No. of favorable No. additional segregating loci alleles inParents favorable alleles Probability that (n) (n/2) in new inbredgenotype occurs* 20 10 14 3 × 10⁻⁵ 24 12 16 2 × 10⁻⁵ 28 14 18 1 × 10⁻⁵32 16 20 8 × 10⁻⁶ 36 18 22 5 × 10⁻⁶ 40 20 24 3 × 10⁻⁶ 44 22 26 2 × 10⁻⁶48 24 28 1 × 10⁻⁶ *Probability that a useful combination exists, doesnot include the probability of identifying this combination if it doesexist.

The possibility of having a usably high probability of being able toidentify this genotype based on replicated field testing would be mostlikely smaller than this and is a function of how large a population ofgenotypes is tested and how testing resources are allocated in thetesting program.

A breeder uses various methods to help determine which plants should beselected from the segregating populations and ultimately which inbredlines will be used to develop hybrids for commercialization. In additionto the knowledge of the germplasm and other skills the breeder uses, apart of the selection process is dependent on experimental designcoupled with the use of statistical analysis. Experimental design andstatistical analysis are used to help determine which plants, whichfamily of plants, and finally which inbred lines and hybrid combinationsare significantly better or different for one or more traits ofinterest. Experimental design methods are used to assess error so thatdifferences between two inbred lines or two hybrid lines can be moreaccurately determined. Statistical analysis includes the calculation ofmean values, determination of the statistical significance of thesources of variation, and the calculation of the appropriate variancecomponents. Either a five or one percent significance level iscustomarily used to determine whether a difference that occurs for agiven trait is real or due to the environment or experimental error. Oneof ordinary skill in the art of plant breeding would know how toevaluate the traits of two plant varieties to determine if there is nosignificant difference between the two traits expressed by thosevarieties. For example, see Fehr, Walt, Principles of CultivarDevelopment, pp. 261-286 (1987) which is incorporated herein byreference. Mean trait values may be used to determine whether traitdifferences are significant, and preferably the traits are measured onplants grown under the same environmental conditions.

Combining ability of a line, as well as the performance of the line perse, is a factor in the selection of improved maize inbreds. Combiningability refers to a line's contribution as a parent when crossed withother lines to form hybrids. The hybrids formed for the purpose ofselecting superior lines are designated test crosses. One way ofmeasuring combining ability is by using breeding values. Breeding valuesare based in part on the overall mean of a number of test crosses. Thismean is then adjusted to remove environmental effects and it is adjustedfor known genetic relationships among the lines.

Once such a line is developed its value to society is substantial sinceit is important to advance the germplasm base as a whole in order tomaintain or improve traits such as yield, disease resistance, pestresistance and plant performance in extreme weather conditions.

SUMMARY OF THE INVENTION

According to the invention, there is provided a hybrid maize plant, andits parts designated as 31G66, produced by crossing two Pioneer Hi-BredInternational, Inc. proprietary inbred maize lines GE587257 andGE565923. These lines, deposited with the American Type CultureCollection, (ATCC), Manassas, Va. 20110, have Accession No. PTA-6465 forGE587257 and Accession No. PTA-6463 for GE565923. This invention thusrelates to the hybrid plant and its parts produced from the seed, andvariants, mutants and trivial modifications of hybrid 31G66. Thisinvention also relates to methods for producing a maize plant containingin its genetic material one or more transgenes and to the transgenicmaize plants and their parts produced by those methods. This inventionfurther relates to methods for producing maize lines derived from hybridmaize line 31G66 and to the maize lines derived by the use of thosemethods. This hybrid maize plant is characterized by high yield withabove average husk coverage, stay green, and root strength.

Definitions

Certain definitions used in the specification are provided below. Inorder to provide a clear and consistent understanding of thespecification and claims, including the scope to be given such terms,the following definitions are provided. NOTE: ABS is in absolute termsand % MN is percent of the mean for the experiments in which the inbredor hybrid was grown. PCT designates that the trait is calculated as apercentage. % NOT designates the percentage of plants that did notexhibit trait. For example, STKLDG % NOT is the percentage of plants ina plot that were not stalk lodged. These designators will follow thedescriptors to denote how the values are to be interpreted. Below arethe descriptors used in the data tables included herein.

ABTSTK=ARTIFICIAL BRITTLE STALK. A count of the number of “snapped”plants per plot following machine snapping. A snapped plant has itsstalk completely snapped at a node between the base of the plant and thenode above the ear. Expressed as percent of plants that did not snap.

ADF═PERCENT ACID DETERGENT FIBER. The percent of dry matter that is aciddetergent fiber in chopped whole plant forage.

ALLELE. Any of one or more alternative forms of a genetic sequence. In adiploid cell or organism, the two alleles of a given sequence occupycorresponding loci on a pair of homologous chromosomes.

ANTROT=ANTHRACNOSE STALK ROT (Colletotnchum graminicola). A 1 to 9visual rating indicating the resistance to Anthracnose Stalk Rot. Ahigher score indicates a higher resistance.

BACKCROSSING. Process in which a breeder crosses a progeny line back toone of the parental genotypes one or more times.

BARPLT=BARREN PLANTS. The percent of plants per plot that were notbarren (lack ears).

BREEDING. The genetic manipulation of living organisms.

BREEDING CROSS. A cross to introduce new genetic material into a plantfor the development of a new variety. For example, one could cross plantA with plant B, wherein plant B would be genetically different fromplant A. After the breeding cross, the resulting F1 plants could then beselfed or sibbed for one, two, three or more times (F1, F2, F3, etc.)until a new inbred variety is developed. For clarification, such newinbred varieties would be within a pedigree distance of one breedingcross of plants A and B.

BRTSTK=BRITTLE STALKS. This is a measure of the stalk breakage near thetime of pollination, and is an indication of whether a hybrid or inbredwould snap or break near the time of flowering under severe winds. Dataare presented as percentage of plants that did not snap.

CLDTST=COLD TEST. The percent of plants that germinate under cold testconditions.

CLN═CORN LETHAL NECROSIS (synergistic interaction of maize chloroticmottle virus (MCMV) in combination with either maize dwarf mosaic virus(MDMV-A or MDMV-B) or wheat streak mosaic virus (WSMV)). A 1 to 9 visualrating indicating the resistance to Corn Lethal Necrosis. A higher scoreindicates a higher resistance.

COMRST=COMMON RUST (Puccinia sorghi). A 1 to 9 visual rating indicatingthe resistance to Common Rust. A higher score indicates a higherresistance.

CP=PERCENT OF CRUDE PROTEIN. The percent of dry matter that is crudeprotein in chopped whole plant forage.

D/D=DRYDOWN. This represents the relative rate at which a hybrid willreach acceptable harvest moisture compared to other hybrids on a 1-9rating scale. A high score indicates a hybrid that dries relatively fastwhile a low score indicates a hybrid that dries slowly.

DIPERS=DIPLODIA EAR MOLD SCORES (Diplodia maydis and Diplodiamacrospora). A 1 to 9 visual rating indicating the resistance toDiplodia Ear Mold. A higher score indicates a higher resistance.

DIPROT=DIPLODIA STALK ROT SCORE. Score of stalk rot severity due toDiplodia (Diplodia maydis). Expressed as a 1 to 9 score with 9 beinghighly resistant.

DM=PERCENT OF DRY MATTER. The percent of dry material in chopped wholeplant silage.

DRPEAR=DROPPED EARS. A measure of the number of dropped ears per plotand represents the percentage of plants that did not drop ears prior toharvest.

D/T=DROUGHT TOLERANCE. This represents a 1-9 rating for droughttolerance, and is based on data obtained under stress conditions. A highscore indicates good drought tolerance and a low score indicates poordrought tolerance.

EARHT=EAR HEIGHT. The ear height is a measure from the ground to thehighest placed developed ear node attachment and is measured incentimeters.

EARMLD=General Ear Mold. Visual rating (1-9 score) where a “1” is verysusceptible and a “9” is very resistant. This is based on overall ratingfor ear mold of mature ears without determining the specific moldorganism, and may not be predictive for a specific ear mold.

EARSZ=EAR SIZE. A 1 to 9 visual rating of ear size. The higher therating the larger the ear size.

EBTSTK=EARLY BRITTLE STALK. A count of the number of “snapped” plantsper plot following severe winds when the corn plant is experiencing veryrapid vegetative growth in the V5-V8 stage. Expressed as percent ofplants that did not snap.

ECB1LF=EUROPEAN CORN BORER FIRST GENERATION LEAF FEEDING (Ostrinianubilalis). A 1 to 9 visual rating indicating the resistance topreflowering leaf feeding by first generation European Corn Borer. Ahigher score indicates a higher resistance.

ECB21T=EUROPEAN CORN BORER SECOND GENERATION INCHES OF TUNNELING(Ostrinia nubilalis). Average inches of tunneling per plant in thestalk.

ECB2SC=EUROPEAN CORN BORER SECOND GENERATION (Ostrinia nubilalis). A 1to 9 visual rating indicating post flowering degree of stalk breakageand other evidence of feeding by European Corn Borer, Second Generation.A higher score indicates a higher resistance.

ECBDPE=EUROPEAN CORN BORER DROPPED EARS (Ostrinia nubilalis). Droppedears due to European Corn Borer. Percentage of plants that did not dropears under second generation corn borer infestation.

EGRWTH=EARLY GROWTH. The relative height and size of a corn seedling atthe 2-4 leaf stage of growth. This is a visual rating (1 to 9), with 1being weak or slow growth, 5 being average growth and 9 being stronggrowth. Taller plants, wider leaves, more green mass and darker colorconstitute higher scores.

ELITE INBRED. An inbred that contributed desirable qualities when usedto produce commercial hybrids. An elite inbred may also be used infurther breeding.

ERTLDG=EARLY ROOT LODGING. Early root lodging is the percentage ofplants that do not root lodge prior to or around anthesis; plants thatlean from the vertical axis at an approximately 30° angle or greaterwould be counted as root lodged.

ERTLPN=Early root lodging is an estimate of the percentage of plantsthat do not root lodge prior to or around anthesis; plants that leanfrom the vertical axis at an approximately 30° angle or greater would beconsidered as root lodged.

ERTLSC=EARLY ROOT LODGING SCORE. Score for severity of plants that leanfrom a vertical axis at an approximate 30 degree angle or greater whichtypically results from strong winds prior to or around floweringrecorded within 2 weeks of a wind event. Expressed as a 1 to 9 scorewith 9 being no lodging.

ESTCNT=EARLY STAND COUNT. This is a measure of the stand establishmentin the spring and represents the number of plants that emerge on perplot basis for the inbred or hybrid.

EYESPT=Eye Spot (Kabatiella zeae or Aureobasidium zeae). A 1 to 9 visualrating indicating the resistance to Eye Spot. A higher score indicates ahigher resistance.

FUSERS=FUSARIUM EAR ROT SCORE (Fusarium moniliforme or Fusariumsubglutinans). A 1 to 9 visual rating indicating the resistance toFusarium ear rot. A higher score indicates a higher resistance.

GDU=Growing Degree Units. Using the Barger Heat Unit Theory, thatassumes that maize growth occurs in the temperature range 50° F.-86° F.and that temperatures outside this range slow down growth; the maximumdaily heat unit accumulation is 36 and the minimum daily heat unitaccumulation is 0. The seasonal accumulation of GDU is a major factor indetermining maturity zones.

GDUSHD=GDU TO SHED. The number of growing degree units (GDUs) or heatunits required for an inbred line or hybrid to have approximately 50percent of the plants shedding pollen and is measured from the time ofplanting. Growing degree units are calculated by the Barger Method,where the heat units for a 24-hour period are:${GDU} = {\frac{\left( {{Max}.\quad{temp}.{+ {{Min}.\quad{temp}.}}} \right)}{2} - 50}$

The highest maximum temperature used is 86° F. and the lowest minimumtemperature used is 50° F. For each inbred or hybrid it takes a certainnumber of GDUs to reach various stages of plant development.

GDUSLK=GDU TO SILK. The number of growing degree units required for aninbred line or hybrid to have approximately 50 percent of the plantswith silk emergence from time of planting. Growing degree units arecalculated by the Barger Method as given in GDU SHD definition.

GENOTYPE. Refers to the genetic constitution of a cell or organism.

GIBERS=GIBBERELLA EAR ROT (PINK MOLD) (Gibberella zeae). A 1 to 9 visualrating indicating the resistance to Gibberella Ear Rot. A higher scoreindicates a higher resistance.

GIBROT=GIBBERELLA STALK ROT SCORE. Score of stalk rot severity due toGibberella (Gibberella zeae). Expressed as a 1 to 9 score with 9 beinghighly resistant.

GLFSPT=Gray Leaf Spot (Cercospora zeae-maydis). A 1 to 9 visual ratingindicating the resistance to Gray Leaf Spot. A higher score indicates ahigher resistance.

GOSWLT=Goss's Wilt (Corynebacterium nebraskense). A 1 to 9 visual ratingindicating the resistance to Goss's Wilt. A higher score indicates ahigher resistance.

GRNAPP=GRAIN APPEARANCE. This is a 1 to 9 rating for the generalappearance of the shelled grain as it is harvested based on such factorsas the color of harvested grain, any mold on the grain, and any crackedgrain. High scores indicate good grain quality.

H/POP=YIELD AT HIGH DENSITY. Yield ability at relatively high plantdensities on 1-9 relative rating system with a higher number indicatingthe hybrid responds well to high plant densities for yield relative toother hybrids. A 1, 5, and 9 would represent very poor, average, andvery good yield response, respectively, to increased plant density.

HCBLT=HELMINTHOSPORIUM CARBONUM LEAF BLIGHT (Helminthosporium carbonum).A 1 to 9 visual rating indicating the resistance to Helminthosporiuminfection. A higher score indicates a higher resistance.

HD SMT=Head Smut (Sphacelotheca reiliana). This score indicates thepercentage of plants not infected.

HSKCVR=HUSK COVER. A 1 to 9 score based upon performance relative to keychecks, with a score of 1 indicating very short husks, tip of ear andkernels showing; 5 is intermediate coverage of the ear under mostconditions, sometimes with thin husk; and a 9 has husks extending andclosed beyond the tip of the ear. Scoring can best be done nearphysiological maturity stage or any time during dry down untilharvested.

KSZDCD=KERNEL SIZE DISCARD. The percent of discard seed; calculated asthe sum of discarded tip kernels and extra large kernels.

LINKAGE. Refers to a phenomenon wherein alleles on the same chromosometend to segregate together more often than expected by chance if theirtransmission was independent.

LINKAGE DISEQUILIBRIUM. Refers to a phenomenon wherein alleles tend toremain together in linkage groups when segregating from parents tooffspring, with a greater frequency than expected from their individualfrequencies.

L/POP=YIELD AT LOW DENSITY. Yield ability at relatively low plantdensities on a 1-9 relative system with a higher number indicating thehybrid responds well to low plant densities for yield relative to otherhybrids. A 1, 5, and 9 would represent very poor, average, and very goodyield response, respectively, to low plant density.

LRTLDG=LATE ROOT LODGING. Late root lodging is the percentage of plantsthat do not root lodge after anthesis through harvest; plants that leanfrom the vertical axis at an approximately 30° angle or greater would becounted as root lodged.

LRTLPN=LATE ROOT LODGING. Late root lodging is an estimate of thepercentage of plants that do not root lodge after anthesis throughharvest; plants that lean from the vertical axis at an approximately 30°angle or greater would be considered as root lodged.

LRTLSC=LATE ROOT LODGING SCORE. Score for severity of plants that leanfrom a vertical axis at an approximate 30 degree angle or greater whichtypically results from strong winds after flowering. Recorded prior toharvest when a root-lodging event has occurred. This lodging results inplants that are leaned or “lodged” over at the base of the plant and donot straighten or “goose-neck” back to a vertical position. Expressed asa 1 to 9 score with 9 being no lodging.

MDMCPX=Maize Dwarf Mosaic Complex (MDMV=Maize Dwarf Mosaic Virus andMCDV=Maize Chlorotic Dwarf Virus). A 1 to 9 visual rating indicating theresistance to Maize Dwarf Mosaic Complex. A higher score indicates ahigher resistance.

MST=HARVEST MOISTURE. The moisture is the actual percentage moisture ofthe grain at harvest.

MSTADV=MOISTURE ADVANTAGE. The moisture advantage of variety #1 overvariety #2 as calculated by: MOISTURE of variety #2—MOISTURE of variety#1=MOISTURE ADVANTAGE of variety #1.

NLFBLT=Northern Leaf Blight (Helminthosporium turcicum or Exserohilumturcicum). A 1 to 9 visual rating indicating the resistance to NorthernLeaf Blight. A higher score indicates a higher resistance.

OILT=GRAIN OIL. Absolute value of oil content of the kernel as predictedby Near-Infrared Transmittance and expressed as a percent of dry matter.

PEDIGREE DISTANCE=Relationship among generations based on theirancestral links as evidenced in pedigrees. May be measured by thedistance of the pedigree from a given starting point in the ancestry.

PLTHT=PLANT HEIGHT. This is a measure of the height of the plant fromthe ground to the tip of the tassel in centimeters.

POLSC=POLLEN SCORE. A 1 to 9 visual rating indicating the amount ofpollen shed. The higher the score the more pollen shed.

POLWT=POLLEN WEIGHT. This is calculated by dry weight of tasselscollected as shedding commences minus dry weight from similar tasselsharvested after shedding is complete.

POP K/A=PLANT POPULATIONS. Measured as 1000s per acre.

POP ADV=PLANT POPULATION ADVANTAGE. The plant population advantage ofvariety #1 over variety #2 as calculated by PLANT POPULATION of variety#2—PLANT POPULATION of variety #1=PLANT POPULATION ADVANTAGE of variety#1.

PRM=PREDICTED RELATIVE MATURITY. This trait, predicted relativematurity, is based on the harvest moisture of the grain. The relativematurity rating is based on a known set of checks and utilizes standardlinear regression analyses and also is referred to as the ComparativeRelative Maturity Rating System that is similar to the MinnesotaRelative Maturity Rating System.

PRMSHD=A relative measure of the growing degree units (GDU) required toreach 50% pollen shed. Relative values are predicted values from thelinear regression of observed GDU's on relative maturity of commercialchecks.

PROT=GRAIN PROTEIN. Absolute value of protein content of the kernel aspredicted by Near-Infrared Transmittance and expressed as a percent ofdry matter.

RTLDG=ROOT LODGING. Root lodging is the percentage of plants that do notroot lodge; plants that lean from the vertical axis as an approximately30° angle or greater would be counted as root lodged.

RTLADV=ROOT LODGING ADVANTAGE. The root lodging advantage of variety #1over variety #2.

SCTGRN=SCATTER GRAIN. A 1 to 9 visual rating indicating the amount ofscatter grain (lack of pollination or kernel abortion) on the ear. Thehigher the score the less scatter grain.

SDGVGR=SEEDLING VIGOR. This is the visual rating (1 to 9) of the amountof vegetative growth after emergence at the seedling stage(approximately five leaves). A higher score indicates better vigor.

SEL IND=SELECTION INDEX. The selection index gives a single measure ofthe hybrid's worth based on information for up to five traits. A maizebreeder may utilize his or her own set of traits for the selectionindex. One of the traits that is almost always included is yield. Theselection index data presented in the tables represent the mean valueaveraged across testing stations.

SIL DMP=SILAGE DRY MATTER. The percent of dry material in chopped wholeplant silage.

SLFBLT=SOUTHERN LEAF BLIGHT (Helminthosporium maydis or Bipolarismaydis). A 1 to 9 visual rating indicating the resistance to SouthernLeaf Blight. A higher score indicates a higher resistance.

SOURST=SOUTHERN RUST (Puccinia polysora). A 1 to 9 visual ratingindicating the resistance to Southern Rust. A higher score indicates ahigher resistance.

STAGRN=STAY GREEN. Stay green is the measure of plant health near thetime of black layer formation (physiological maturity). A high scoreindicates better late-season plant health.

STARCH=PERCENT OF STARCH. The percent of dry matter that is starch inchopped whole plant forage.

STDADV=STALK STANDING ADVANTAGE. The advantage of variety #1 overvariety #2 for the trait STK CNT.

STKCNT=NUMBER OF PLANTS. This is the final stand or number of plants perplot.

STKLDG=STALK LODGING REGULAR. This is the percentage of plants that didnot stalk lodge (stalk breakage at regular harvest (when grain moistureis between about 20 and 30%)) as measured by either natural lodging orpushing the stalks and determining the percentage of plants that breakbelow the ear.

STKLDL=LATE STALK LODGING. This is the percentage of plants that did notstalk lodge (stalk breakage) at or around late season harvest (whengrain moisture is between about 15 and 18%) as measured by eithernatural lodging or pushing the stalks and determining the percentage ofplants that break below the ear.

STKLDS=STALK LODGING SCORE. A plant is considered as stalk lodged if thestalk is broken or crimped between the ear and the ground. This can becaused by any or a combination of the following: strong winds late inthe season, disease pressure within the stalks, ECB damage orgenetically weak stalks. This trait should be taken just prior to or atharvest. Expressed on a 1 to 9 scale with 9 being no lodging.

STLPCN=STALK LODGING REGULAR. This is an estimate of the percentage ofplants that did not stalk lodge (stalk breakage at regular harvest (whengrain moisture is between about 20 and 30%)) as measured by eithernatural lodging or pushing the stalks and determining the percentage ofplants that break below the ear.

STRT=GRAIN STARCH. Absolute value of starch content of the kernel aspredicted by Near-Infrared Transmittance and expressed as a percent ofdry matter.

STWWLT=Stewart's Wilt (Erwinia stewartii). A 1 to 9 visual ratingindicating the resistance to Stewart's Wilt. A higher score indicates ahigher resistance.

TASBLS=TASSEL BLAST. A 1 to 9 visual rating was used to measure thedegree of blasting (necrosis due to heat stress) of the tassel at thetime of flowering. A 1 would indicate a very high level of blasting attime of flowering, while a 9 would have no tassel blasting.

TASSZ=TASSEL SIZE. A 1 to 9 visual rating was used to indicate therelative size of the tassel. The higher the rating the larger thetassel.

TASWT=TASSEL WEIGHT. This is the average weight of a tassel (grams) justprior to pollen shed.

TDM/HA=TOTAL DRY MATTER PER HECTARE. Yield of total dry plant materialin metric tons per hectare.

TEXEAR=EAR TEXTURE. A 1 to 9 visual rating was used to indicate therelative hardness (smoothness of crown) of mature grain. A 1 would bevery soft (extreme dent) while a 9 would be very hard (flinty or verysmooth crown).

TILLER=TILLERS. A count of the number of tillers per plot that couldpossibly shed pollen was taken. Data are given as a percentage oftillers: number of tillers per plot divided by number of plants perplot.

TST WT=TEST WEIGHT (UNADJUSTED). The measure of the weight of the grainin pounds for a given volume (bushel).

TSWADV=TEST WEIGHT ADVANTAGE. The test weight advantage of variety #1over variety #2.

WIN M %=PERCENT MOISTURE WINS.

-   WIN Y %=PERCENT YIELD WINS.

YIELD=YIELD OF SILAGE. Yield in tons per acre at 30% dry matter.

YIELD BU/A=YIELD (BUSHELSIACRE). Yield of the grain at harvest inbushels per acre adjusted to 15% moisture.

YLDADV=YIELD ADVANTAGE. The yield advantage of variety #1 over variety#2 as calculated by: YIELD of variety #1−YIELD variety #2=yieldadvantage of variety #1.

YLD SC=YIELD SCORE. A 1 to 9 visual rating was used to give a relativerating for yield based on plot ear piles. The higher the rating thegreater visual yield appearance.

Definitions for Area of Adaptability

When referring to area of adaptability, such term is used to describethe location with the environmental conditions that would be well suitedfor this maize line. Area of adaptability is based on a number offactors, for example: days to maturity, insect resistance, diseaseresistance, and drought resistance. Area of adaptability does notindicate that the maize line will grow in every location within the areaof adaptability or that it will not grow outside the area.

-   Central Corn Belt: Iowa, Illinois, Indiana-   Drylands: non-irrigated areas of North Dakota, South Dakota,    Nebraska, Kansas, Colorado and Oklahoma-   Eastern U.S.: Ohio, Pennsylvania, Delaware, Maryland, Virginia, and    West Virginia-   North central U.S.; Minnesota and Wisconsin-   Northeast: Michigan, New York, Vermont, and Ontario and Quebec    Canada-   Northwest U.S.: North Dakota, South Dakota, Wyoming, Washington,    Oregon, Montana, Utah, and Idaho-   South central U.S.: Missouri, Tennessee, Kentucky, Arkansas-   Southeast U.S.: North Carolina, South Carolina, Georgia, Florida,    Alabama, Mississippi, and Louisiana-   Southwest U.S.: Texas, Oklahoma, New Mexico, Arizona-   Western U.S.: Nebraska, Kansas, Colorado, and California-   Maritime Europe: France, Germany, Belgium, and Austria

DETAILED DESCRIPTION OF THE INVENTION

Inbred maize lines are typically developed for use in the production ofhybrid maize lines. Maize hybrids need to be highly homogeneous,heterozygous and reproducible to be useful as commercial hybrids. Thereare many analytical methods available to determine the heterozygousnature and the identity of these lines.

The oldest and most traditional method of analysis is the observation ofphenotypic traits. The data is usually collected in field experimentsover the life of the maize plants to be examined. Phenotypiccharacteristics most often observed are for traits associated with plantmorphology, ear and kernel morphology, insect and disease resistance,maturity, and yield.

In addition to phenotypic observations, the genotype of a plant can alsobe examined. A plant's genotype can be used to identify plants of thesame variety or a related variety. For example, the genotype can be usedto determine the pedigree of a plant. There are many laboratory-basedtechniques available for the analysis, comparison and characterizationof plant genotype; among these are Isozyme Electrophoresis, RestrictionFragment Length Polymorphisms (RFLPs), Randomly Amplified PolymorphicDNAs (RAPDs), Arbitrarily Primed Polymerase Chain Reaction (AP-PCR), DNAAmplification Fingerprinting (DAF), Sequence Characterized AmplifiedRegions (SCARs), Amplified Fragment Length Polymorphisms (AFLPs), SimpleSequence Repeats (SSRs) which are also referred to as Microsatellites,and Single Nucleotide Polymorphisms (SNPs).

Isozyme Electrophoresis and RFLPs as discussed in Lee, M., “Inbred Linesof Maize and Their Molecular Markers,” The Maize Handbook,(Springer-Verlag, New York, Inc. 1994, at 423-432) incorporated hereinby reference, have been widely used to determine genetic composition.Isozyme Electrophoresis has a relatively low number of available markersand a low number of allelic variants. RFLPs allow more discriminationbecause they have a higher degree of allelic variation in maize and alarger number of markers can be found. Both of these methods have beeneclipsed by SSRs as discussed in Smith et al., “An evaluation of theutility of SSR loci as molecular markers in maize (Zea mays L.):comparisons with data from RFLPs and pedigree”, Theoretical and AppliedGenetics (1997) Vol. 95 at 163-173 and by Pejic et al., “Comparativeanalysis of genetic similarity among maize inbreds detected by RFLPs,RAPDs, SSRs, and AFLPs,” Theoretical and Applied Genetics (1998) at1248-1255 incorporated herein by reference. SSR technology is moreefficient and practical to use than RFLPs; more marker loci can beroutinely used and more alleles per marker locus can be found using SSRsin comparison to RFLPs. Single Nucleotide Polymorphisms may also be usedto identify the unique genetic composition of the invention and progenylines retaining that unique genetic composition. Various molecularmarker techniques may be used in combination to enhance overallresolution.

Maize DNA molecular marker linkage maps have been rapidly constructedand widely implemented in genetic studies. One such study is describedin Boppenmaier, et at., “Comparisons among strains of inbreds forRFLPs”, Maize Genetics Cooperative Newsletter, 65:1991, pg. 90, isincorporated herein by reference.

Pioneer Brand Hybrid 31G66 is characterized by high yield particularlyacross low yield environments. The hybrid also provides above averagehusk coverage and above average root strength. Hybrid 31G66 furtherdemonstrates above average tolerance to Gray Leaf Spot, above averagetolerance to Northern Leaf Blight and excellent tolerance to FusariumEar Rot. The hybrid is particularly suited to the Southcentral,Southeast, Southwest, Eastern, and Western areas of the United States.

Pioneer Brand Hybrid 31G66 is a single cross, yellow endosperm, flintdent maize hybrid. Hybrid 31G66 has a relative maturity of approximately118 based on the Comparative Relative Maturity Rating System for harvestmoisture of grain.

This hybrid has the following characteristics based on the datacollected primarily at Johnston, Iowa.

TABLE 1 VARIETY DESCRIPTION INFORMATION VARIETY = 31G66  1. TYPE:(describe intermediate types in Comments section): 3 1 = Sweet 2 = Dent3 = Flint 4 = Flour 5 = Pop and 6 = Ornamental  2. MATURITY: DAYS HEATUNITS 058 1,457.0 From emergence to 50% of plants in silk 058 1,457.0From emergence to 50% of plants in pollen 001 0,037.0 From 10% to 90%pollen shed From 50% silk to harvest at 25% moisture Standard Sample  3.PLANT: Deviation Size 336.7 cm Plant Height (to tassel tip) 13.61 15126.7 cm Ear Height (to base of top ear node) 11.30 15 20.1 cm Length ofTop Ear Internode 1.79 15 0.0 Average Number of Tillers per plant 0.04 31.0 Average Number of Ears per Stalk 0.07 3 1.0 Anthocyanin of BraceRoots: 1 = Absent 2 = Faint 3 = Moderate 4 = Dark 5 = Very Dark StandardSample  4. LEAF: Deviation Size 11.9 cm Width of Ear Node Leaf 1.36 1592.3 cm Length of Ear Node Leaf 3.69 15 06.9 Number of leaves above TopEar 0.46 15 020.2 Leaf Angle (measure from 2nd leaf above ear 3.53 15 atanthesis to stalk above leaf) (Degrees) Leaf Color Dark Green (Munsellcode) 7.5GY34 3.0 Leaf Sheath Pubescence (Rate on scale from 1 = none to9 = like peach fuzz) Standard Sample  5. TASSEL: Deviation Size 04.9Number of Primary Lateral Branches 1.87 15 025.5 Branch Angle fromCentral Spike 8.63 15 71.1 cm Tassel Length (from top leaf collar totassel tip) 5.79 15 6 Pollen Shed (rate on scale from 0 = male sterileto 9 = heavy shed) Anther Color Yellow (Munsell code) 5Y8.58 Glume ColorLight Green (Munsell code) 5GY66 1 Bar Glumes (Glume Bands): 1 = Absent2 = Present 29.3 cm Peduncle Length (from top leaf to basal branches)3.09 15  6a. EAR (Unhusked Data): Silk Color (3 days after emergence)Light Green (Munsell code) 2.5GY88 Fresh Husk Color Light Green (Munsellcode) 5GY68 (25 days after 50% silking) Dry Husk Color Buff (Munsellcode) 5Y92 (65 days after 50% silking) 2 Position of Ear at Dry HuskStage: 1 = Upright 2 = Horizontal 3 = Pendant 7 Husk Tightness (Rate ofScale from 1 = very loose to 9 = very tight) 2 Husk Extension (atharvest): 1 = Short (ears exposed) 2 = Medium (<8 cm) 3 = Long (8-10 cmbeyond ear tip) 4 = Very Long (>10 cm) Standard Sample  6b. EAR (HuskedEar Data): Deviation Size 18.4 cm Ear Length 1.99 15 48.9 mm EarDiameter at mid-point 2.33 15 220.3 gm Ear Weight 52.06 15 17.7 Numberof Kernel Rows 1.67 15 2 Kernel Rows: 1 = Indistinct 2 = Distinct 1 RowAlignment: 1 = Straight 2 = Slightly Curved 3 = Spiral 11.3 cm ShankLength 2.26 15 2 Ear Taper: 1 = Slight Cylind. 2 = Average 3 = ExtremeConic. Standard Sample  7. KERNEL (Dried): Deviation Size 13.3 mm KernelLength 0.70 15 7.7 mm Kernel Width 0.70 15 4.3 mm Kernel Thickness 0.4615 22.0 % Round Kernels (Shape Grade) 3.90 3 1 Aleurone Color Pattern: 1= Homozygous 2 = Segregating Aleurone Color Yellow (Munsell code)10YR814 Hard Endosperm Color Yellow (Munsell code) 10YR714 3 EndospermType: Normal Starch 1 = Sweet (su1) 2 = Extra Sweet (sh2) 3 = NormalStarch 4 = High Amylose Starch 5 = Waxy Starch 6 = High Protein 7 = HighLysine 8 = Super Sweet (se) 9 = High Oil 10 = Other    32.0 gm Weightper 100 Kernels (unsized sample) 4.58 3 Standard Sample  8. COB:Deviation Size 25.1 mm Cob Diameter at mid-point 1.16 15 Cob Color Pink(Munsell code) 10R66  9. DISEASE RESISTANCE (Rate from 1 (mostsusceptible) to 9 (most resistant); leave blank if not tested; leaveRace or Strain Options blank if polygenic): A. Leaf Blights, Wilts, andLocal Infection Diseases Anthracnose Leaf Blight (Colletotrichumgraminicola) 5 Common Rust (Puccinia sorghi) Common Smut (Ustilagomaydis) Eyespot (Kabatiella zeae) Goss's Wilt (Clavibacter michiganensespp. nebraskense) 6 Gray Leaf Spot (Cercospora zeae-maydis)Helminthosporium Leaf Spot (Bipolaris zeicola)  Race    6 Northern LeafBlight (Exserohilum turcicum)  Race    5 Southern Leaf Blight (Bipolarismaydis)  Race    4 Southern Rust (Puccinia polysora) Stewart's Wilt(Erwinia stewartii) Other (Specify)    B. Systemic Diseases 5 CornLethal Necrosis (MCMV and MDMV) 9 Head Smut (Sphacelotheca reiliana)Maize Chlorotic Dwarf Virus (MDV) Maize Chlorotic Mottle Virus (MCMV) 4Maize Dwarf Mosaic Virus (MDMV) Sorghum Downy Mildew of Corn(Peronosclerospora sorghi) Other (Specify)    C. Stalk Rots 5Anthracnose Stalk Rot (Colletotrichum graminicola) Diplodia Stalk Rot(Stenocarpella maydis) Fusarium Stalk Rot (Fusarium moniliforme)Gibberella Stalk Rot (Gibberella zeae) Other (Specify)    D. Ear andKernel Rots Aspergillus Ear and Kernel Rot (Aspergillus flavus) 4Diplodia Ear Rot (Stenocarpella maydis) 7 Fusarium Ear and Kernel Rot(Fusarium moniliforme) Gibberella Ear Rot (Gibberella zeae) Other(Specify)    10. INSECT RESISTANCE (Rate from 1 (most susceptible) to 9(most resistant): (leave blank if not tested): Banks grass Mite(Oligonychus pratensis) Corn Worm (Helicoverpa zea) Leaf Feeding SilkFeeding mg larval wt. Ear Damage Corn Leaf Aphid (Rhopalosiphum maidis)Corn Sap Beetle (Carpophilus dimidiatus European Corn Borer (Ostrinianubilalis) 4 1st Generation (Typically Whorl Leaf Feeding) 4 2ndGeneration (Typically Leaf Sheath-Collar Feeding) Stalk Tunneling cmtunneled/plant Fall Armyworm (Spodoptera fruqiperda) Leaf Feeding SilkFeeding mg larval wt. Maize Weevil (Sitophilus zeamaize) NorthernRootworm (Diabrotica barberi) Southern Rootworm (Diabroticaundecimpunctata) Southwestern Corn Borer (Diatreaea grandiosella) LeafFeeding Stalk Tunneling cm tunneled/plant Two-spotted Spider Mite(Tetranychus urticae) Western Rootworm (Diabrotica virgifrea virgifera)Other (Specify)    11. AGRONOMIC TRAITS: 6 Staygreen (65 days afteranthesis. Rate on a scale from 1 = worst to 9 = excellent) % DroppedEars (at 65 days after anthesis) % Pre-anthesis Brittle Snapping 17 %Pre-anthesis Root Lodging 11 % Post-anthesis Root Lodging (at 65 daysafter anthesis) 29 % Post-anthesis Stalk Lodging 12,507 Kg/ha Yield (at12-13% grain moisture) *In interpreting the foregoing colordesignations, reference may be made to the Munsell Glossy Book of Color,a standard color reference (Kollmorgen Inst. Corp. New Windsor, NY).

Research Comparisons for Pioneer Hybrid 31 G66

Comparisons of characteristics for Pioneer Brand Hybrid 31G66 were madeagainst Hybrid 31G98, 31N27, 31R88, 3223, 32B33 and 32K61.

Table 2A compares Pioneer Brand Hybrid 31G66 and Pioneer Brand Hybrid31G98, a hybrid with a similar area of adaptation. Significantdifferences between Hybrid 31G66 and Hybrid 31G98 include yield,resistance to artificial brittle stalk, stay green, husk cover,resistance to Gray Leaf Spot, resistance to Southern Leaf Blight,resistance to Fusarium Ear Rot, and resistance to Head Smut.

Table 2B compares Pioneer Brand Hybrid 31G66 and Pioneer Brand Hybrid31N27, a hybrid with a similar area of adaptation. The tabledemonstrates significant differences between Hybrid 31G66 and Hybrid31N27 which include early growth, plant height, ear height, and numberof growing degree units to pollen shed, and number of growing degreeunits to silk emergence.

Table 2C compares Pioneer Brand Hybrid 31G66 and Pioneer Brand Hybrid31R88, a hybrid with a similar area of adaptation. Significantdifferences between Hybrid 31G66 and Hybrid 31R88 include yield, harvestmoisture, early growth, ear height, husk cover, and resistance toFusarium Ear Rot.

Table 2D compares Pioneer Brand Hybrid 31G66 and Pioneer Brand Hybrid3223, a closely related hybrid with a similar area of adaptation. Thetable demonstrates significant differences between Hybrid 31G66 andHybrid 3233 which include yield, ear height, resistance to artificialbrittle stalk, resistance to Gray Leaf Spot, resistance to Southern LeafBlight, and resistance to Fusarium Ear Rot.

Table 2E compares Pioneer Brand Hybrid 31G66 and Pioneer Brand Hybrid32B33, a closely related hybrid. Significant differences between Hybrid31G66 and Hybrid 32B33 include number of growing degree units to pollenshed, number of growing degree units to silk emergence, stay green, huskcover, resistance to Gray Leaf Spot, resistance to Anthracnose StalkRot, and resistance to Fusarium Ear Rot.

Table 2F compares Pioneer Brand Hybrid 31G66 and Pioneer Brand Hybrid32K61, a closely related hybrid with a similar area of adaptation. Thetable shows significant differences between Hybrid 31G66 and Hybrid32K61 which include yield, early growth, resistance to artificialbrittle stalk, stay green, husk cover, and resistance to Fusarium EarRot.

TABLE 2A HYBRID COMPARISON Variety #1: 31G66 Variety #2: 31G98 YIELDYIELD MST EGRWTH ESTCNT GDUSHD GDUSLK STKCNT PLTHT EARHT STAGRN LRTLSCBU/A 56# BU/A 56# PCT SCORE COUNT GDU GDU COUNT CM CM SCORE SCORE StatABS % MN % MN % MN % MN % MN % MN % MN % MN % MN % MN ABS Mean1 199.5106.6 101.6 107.4 103.2 101.4 100.7 100.7 102.3 102.1 127.8 5.0 Mean2191.6 101.9 97.9 92.5 100.4 102.2 101.8 100.4 100.5 103.7 99.6 2.0 Locs117 117 118 16 15 17 12 197 31 31 34 1 Reps 127 127 128 19 27 23 15 29038 38 38 1 Diff 7.9 4.7 −3.7 14.9 2.9 −0.8 −1.1 0.4 1.8 −1.6 28.3 3.0Prob 0.000 0.000 0.000 0.001 0.191 0.534 0.185 0.380 0.072 0.305 0.000STKLDS STKLDG EBTSTK ABTSTK TSTWT GLFSPT NLFBLT SLFBLT ANTROT CLN MDMCPXFUSERS SCORE % NOT % NOT % NOT LB/BU SCORE SCORE SCORE SCORE SCORE SCORESCORE Stat ABS % MN % MN % MN ABS ABS ABS ABS ABS ABS ABS ABS Mean1 7.0107.8 102.3 138.9 55.7 6.3 5.8 4.9 4.7 5.0 4.0 7.0 Mean2 7.1 109.4 101.462.8 56.2 5.2 5.8 4.1 4.3 4.5 3.0 5.2 Locs 9 1 3 8 80 6 4 6 6 1 2 9 Reps9 1 3 29 91 9 7 9 10 4 4 16 Diff −0.1 −1.6 0.9 76.1 −0.5 1.1 0.0 0.8 0.40.5 1.0 1.8 Prob 0.917 0.845 0.001 0.020 0.016 1.000 0.011 0.224 0.2950.002 HD DIPERS COMRST SOURST ECB1LF ECB2SC HSKCVR GIBROT DIPROT BRTSTKSMT ERTLPN LRTLPN SCORE SCORE SCORE SCORE SCORE SCORE SCORE SCORE % NOT% NOT % NOT % NOT Stat ABS ABS ABS ABS ABS ABS ABS ABS ABS ABS ABS ABSMean1 4.5 5.0 4.0 3.8 4.3 6.7 5.0 4.0 100.0 95.1 82.7 89.2 Mean2 4.0 5.03.5 3.7 4.3 5.3 4.5 3.0 98.2 98.8 72.4 85.8 Locs 2 1 1 2 6 16 1 1 1 6 1112 Reps 4 1 2 6 10 19 2 2 2 9 16 13 Diff 0.5 0.0 0.5 0.2 0.1 1.4 0.5 1.01.8 −3.7 10.3 3.3 Prob 1.000 0.874 0.842 0.000 0.048 0.145 0.339

TABLE 2B HYBRID COMPARISON Variety #1: 31G66 Variety #2: 31N27 YIELDYIELD MST EGRWTH ESTCNT GDUSHD GDUSLK STKCNT PLTHT EARHT STAGRN STKLDGBU/A 56# BU/A 56# PCT SCORE COUNT GDU GDU COUNT CM CM SCORE % NOT StatABS % MN % MN % MN % MN % MN % MN % MN % MN % MN % MN % MN Mean1 198.9105.9 101.5 105.6 105.4 103.1 102.9 100.9 101.5 102.1 122.0 107.8 Mean2197.4 104.3 100.4 85.8 101.5 100.9 101.3 100.7 95.3 90.5 112.3 109.4Locs 102 102 102 11 11 20 15 178 27 27 28 1 Reps 112 112 112 13 23 25 17271 34 34 32 1 Diff 1.5 1.6 −1.1 19.7 3.9 2.3 1.6 0.2 6.2 11.6 9.8 −1.6Prob 0.564 0.298 0.154 0.010 0.020 0.025 0.000 0.608 0.000 0.000 0.136ABTSTK TSTWT GLFSPT NLFBLT SLFBLT ANTROT CLN MDMCPX FUSERS DIPERS SOURSTECB1LF % NOT LB/BU SCORE SCORE SCORE SCORE SCORE SCORE SCORE SCORE SCORESCORE Stat % MN ABS ABS ABS ABS ABS ABS ABS ABS ABS ABS ABS Mean1 138.955.5 6.3 5.8 4.9 4.6 5.0 4.0 7.0 4.5 4.0 3.8 Mean2 132.1 57.0 6.0 5.66.7 4.8 4.0 3.8 6.5 3.5 6.0 3.7 Locs 8 66 6 4 6 5 1 2 9 2 1 2 Reps 29 779 7 9 10 4 4 16 4 2 6 Diff 6.9 −1.5 0.3 0.1 −1.8 −0.2 1.0 0.3 0.5 1.0−2.0 0.2 Prob 0.534 0.000 0.542 0.789 0.001 0.749 0.500 0.160 0.2950.874 HD ECB2SC HSKCVR GIBROT DIPROT BRTSTK SMT ERTLPN LRTLPN SCORESCORE SCORE SCORE % NOT % NOT % NOT % NOT Stat ABS ABS ABS ABS ABS ABSABS ABS Mean1 4.3 6.8 5.0 4.0 100.0 95.1 82.7 89.2 Mean2 5.4 6.6 5.5 5.5100.0 96.3 85.9 93.3 Locs 6 14 1 1 1 6 11 12 Reps 10 17 2 2 2 9 15 13Diff −1.1 0.2 −0.5 −1.5 0.0 −1.2 −3.2 −4.2 Prob 0.108 0.459 0.518 0.6160.318

TABLE 2C HYBRID COMPARISON Variety #1: 31G66 Variety #2: 31R88 YIELDYIELD MST EGRWTH ESTCNT GDUSHD GDUSLK STKCNT PLTHT EARHT STAGRN LRTLSCBU/A 56# BU/A 56# PCT SCORE COUNT GDU GDU COUNT CM CM SCORE SCORE StatABS % MN % MN % MN % MN % MN % MN % MN % MN % MN % MN ABS Mean1 199.9106.1 101.6 107.4 103.2 101.4 100.7 100.7 102.3 102.1 127.8 5.0 Mean2185.1 97.8 106.9 88.4 102.1 99.5 101.5 100.7 103.8 109.0 117.7 5.0 Locs120 120 120 16 15 17 12 198 31 31 34 1 Reps 130 130 130 18 27 21 13 29038 38 38 1 Diff 14.8 8.4 5.2 19.0 1.1 2.0 −0.7 0.0 −1.5 −6.9 10.1 0.0Prob 0.000 0.000 0.000 0.000 0.545 0.081 0.355 0.915 0.184 0.001 0.036STKLDS STKLDG EBTSTK ABTSTK TSTWT GLFSPT NLFBLT SLFBLT ANTROT CLN MDMCPXFUSERS SCORE % NOT % NOT % NOT LB/BU SCORE SCORE SCORE SCORE SCORE SCORESCORE Stat ABS % MN % MN % MN ABS ABS ABS ABS ABS ABS ABS ABS Mean1 7.0107.8 102.3 138.9 55.8 6.3 5.8 4.9 4.7 5.0 4.0 7.0 Mean2 7.6 107.8 105.3142.9 55.8 6.9 5.4 6.7 5.5 4.0 3.3 5.6 Locs 9 1 3 8 79 6 4 6 6 1 2 9Reps 9 1 3 29 90 9 7 9 11 4 4 16 Diff −0.6 0.0 −3.0 −4.0 0.0 −0.7 0.4−1.8 −0.8 1.0 0.8 1.4 Prob 0.547 0.233 0.591 0.984 0.025 0.391 0.0050.233 0.205 0.050 HD DIPERS COMRST SOURST ECB1LF ECB2SC HSKCVR GIBROTDIPROT BRTSTK SMT ERTLPN LRTLPN SCORE SCORE SCORE SCORE SCORE SCORESCORE SCORE % NOT % NOT % NOT % NOT Stat ABS ABS ABS ABS ABS ABS ABS ABSABS ABS ABS ABS Mean1 4.5 5.0 4.0 3.8 4.3 6.6 5.0 4.0 100.0 95.1 82.789.2 Mean2 3.3 4.0 2.0 5.2 4.2 4.5 8.0 4.0 100.0 98.7 84.5 83.8 Locs 2 11 2 6 17 1 1 1 6 11 12 Reps 4 1 2 6 10 20 2 2 2 9 14 13 Diff 1.3 1.0 2.0−1.3 0.1 2.2 −3.0 0.0 0.0 −3.6 −1.8 5.4 Prob 0.500 0.156 0.793 0.0000.075 0.660 0.392

TABLE 2D HYBRID COMPARISON Variety #1: 31G66 Variety #2: 3223 YIELDYIELD MST EGRWTH ESTCNT GDUSHD GDUSLK STKCNT BU/A 56# BU/A 56# PCT SCORECOUNT GDU GDU COUNT Stat ABS % MN % MN % MN % MN % MN % MN % MN Mean1201.9 105.2 101.9 109.1 97.2 101.9 100.9 100.2 Mean2 183.9 95.3 92.495.6 104.6 104.7 102.2 100.6 Locs 69 69 70 13 4 10 6 114 Reps 71 71 7216 4 13 6 156 Diff 18.0 9.9 −9.5 13.5 −7.5 −2.8 −1.3 −0.5 Prob 0.0000.000 0.000 0.002 0.256 0.028 0.224 0.358 PLTHT EARHT STAGRN LRTLSCSTKLDS STKLDG EBTSTK ABTSTK CM CM SCORE SCORE SCORE % NOT % NOT % NOTStat % MN % MN % MN ABS ABS % MN % MN % MN Mean1 104.1 104.1 139.6 5.07.0 107.8 102.3 144.9 Mean2 98.2 110.7 72.0 6.0 5.4 73.5 105.2 97.3 Locs17 17 20 1 9 1 3 5 Reps 22 22 22 1 9 1 3 14 Diff 5.9 −6.6 67.5 −1.0 1.634.3 −2.9 47.6 Prob 0.000 0.011 0.000 0.133 0.437 0.028 TSTWT GLFSPTNLFBLT SLFBLT ANTROT CLN MDMCPX FUSERS LB/BU SCORE SCORE SCORE SCORESCORE SCORE SCORE Stat ABS ABS ABS ABS ABS ABS ABS ABS Mean1 55.7 6.35.5 5.0 5.0 5.0 4.0 7.1 Mean2 56.3 2.4 6.0 3.3 3.8 4.5 3.8 5.9 Locs 49 41 5 4 1 2 5 Reps 52 6 2 7 7 4 4 9 Diff −0.5 3.9 −0.5 1.7 1.3 0.5 0.3 1.2Prob 0.055 0.010 0.005 0.063 0.500 0.042 HD COMRST ECB1LF ECB2SC HSKCVRBRTSTK SMT ERTLPN LRTLPN SCORE SCORE SCORE SCORE % NOT % NOT % NOT % NOTStat ABS ABS ABS ABS ABS ABS ABS ABS Mean1 5.0 5.0 3.4 6.5 100.0 93.087.0 100.0 Mean2 4.0 3.3 4.1 4.5 96.6 97.8 88.0 100.0 Locs 1 1 3 12 1 35 2 Reps 1 3 5 13 2 6 7 2 Diff 1.0 1.7 −0.7 2.0 3.4 −4.8 −1.0 0.0 Prob0.184 0.000 0.111 0.704 1.000

TABLE 2E HYBRID COMPARISON Variety #1: 31G66 Variety #2: 32B33 YIELDYIELD MST EGRWTH ESTCNT GDUSHD GDUSLK STKCNT PLTHT BU/A 56# BU/A 56# PCTSCORE COUNT GDU GDU COUNT CM Stat ABS % MN % MN % MN % MN % MN % MN % MN% MN Mean1 199.9 106.2 101.7 107.8 103.2 103.1 102.9 100.8 102.3 Mean2197.4 103.7 99.1 105.2 102.7 101.0 101.4 101.2 99.2 Locs 119 119 119 1515 20 15 199 31 Reps 129 129 129 18 27 25 17 292 38 Diff 2.5 2.5 −2.62.6 0.5 2.2 1.5 −0.3 3.0 Prob 0.320 0.077 0.000 0.686 0.620 0.030 0.0080.386 0.001 EARHT STAGRN STKLDS STKLDG EBTSTK ABTSTK TSTWT GLFSPT NLFBLTCM SCORE SCORE % NOT % NOT % NOT LB/BU SCORE SCORE Stat % MN % MN ABS %MN % MN % MN ABS ABS ABS Mean1 102.1 127.8 7.0 107.8 102.3 138.9 55.76.3 5.8 Mean2 99.6 100.1 7.2 109.4 105.3 118.0 56.5 5.0 5.8 Locs 31 34 91 3 8 79 6 4 Reps 38 38 9 1 3 29 90 9 7 Diff 2.6 27.7 −0.2 −1.6 −3.021.0 −0.8 1.3 0.0 Prob 0.074 0.002 0.796 0.235 0.067 0.000 0.014 1.000SLFBLT ANTROT CLN MDMCPX FUSERS DIPERS COMRST SOURST ECB1LF SCORE SCORESCORE SCORE SCORE SCORE SCORE SCORE SCORE Stat ABS ABS ABS ABS ABS ABSABS ABS ABS Mean1 4.9 4.7 5.0 4.0 7.0 4.5 5.0 4.0 3.8 Mean2 6.9 3.8 3.52.8 6.0 4.5 4.0 2.5 2.8 Locs 6 6 1 2 9 2 1 1 2 Reps 9 11 4 4 16 4 1 2 6Diff −2.0 0.8 1.5 1.3 1.0 0.0 1.0 1.5 1.0 Prob 0.010 0.020 0.126 0.0461.000 0.205 HD ECB2SC HSKCVR GIBROT DIPROT BRTSTK SMT ERTLPN LRTLPNSCORE SCORE SCORE SCORE % NOT % NOT % NOT % NOT Stat ABS ABS ABS ABS ABSABS ABS ABS Mean1 4.3 6.6 5.0 4.0 100.0 95.1 82.7 89.2 Mean2 4.3 5.0 3.54.5 99.1 96.3 81.6 88.3 Locs 6 17 1 1 1 6 11 12 Reps 10 20 2 2 2 9 15 13Diff 0.1 1.7 1.5 −0.5 0.9 −1.2 1.1 0.8 Prob 0.886 0.000 0.646 0.8810.896

TABLE 2F HYBRID COMPARISON Variety #1: 31G66 Variety #2: 32K61 YIELDYIELD MST EGRWTH ESTCNT GDUSHD GDUSLK STKCNT BU/A 56# BU/A 56# PCT SCORECOUNT GDU GDU COUNT Stat ABS % MN % MN % MN % MN % MN % MN % MN Mean1199.2 105.8 101.6 105.6 105.6 101.4 100.7 100.7 Mean2 174.6 92.3 92.6127.2 104.6 102.1 101.0 101.0 Locs 102 102 102 11 7 17 12 165 Reps 112112 112 14 15 23 14 250 Diff 24.5 13.6 −9.0 −21.6 1.0 −0.6 −0.3 −0.3Prob 0.000 0.000 0.000 0.032 0.116 0.342 0.570 0.497 PLTHT EARHT STAGRNSTKLDG ABTSTK TSTWT GLFSPT NLFBLT CM CM SCORE % NOT % NOT LB/BU SCORESCORE Stat % MN % MN % MN % MN % MN ABS ABS ABS Mean1 101.5 102.1 122.0107.8 138.9 55.6 6.3 5.8 Mean2 98.9 96.7 95.7 94.9 113.6 57.8 5.8 5.3Locs 26 26 28 1 8 67 6 4 Reps 33 33 32 1 29 78 9 7 Diff 2.6 5.3 26.312.9 25.3 −2.2 0.4 0.5 Prob 0.022 0.007 0.000 0.039 0.000 0.363 0.092SLFBLT ANTROT CLN MDMCPX FUSERS DIPERS SOURST ECB1LF SCORE SCORE SCORESCORE SCORE SCORE SCORE SCORE Stat ABS ABS ABS ABS ABS ABS ABS ABS Mean14.9 4.6 5.0 4.0 7.0 4.5 4.0 3.8 Mean2 5.2 4.6 4.5 3.3 4.9 4.0 4.0 3.8Locs 6 5 1 2 9 2 1 2 Reps 9 10 4 4 16 4 2 6 Diff −0.3 0.0 0.5 0.8 2.10.5 0.0 0.0 Prob 0.542 1.000 0.500 0.004 0.500 1.000 HD ECB2SC HSKCVRGIBROT DIPROT BRTSTK SMT ERTLPN LRTLPN SCORE SCORE SCORE SCORE % NOT %NOT % NOT % NOT Stat ABS ABS ABS ABS ABS ABS ABS ABS Mean1 4.3 6.8 5.04.0 100.0 95.1 83.5 89.2 Mean2 3.9 5.6 8.0 6.0 100.0 95.3 85.5 95.8 Locs6 14 1 1 1 6 10 12 Reps 10 17 2 2 2 9 14 13 Diff 0.4 1.2 −3.0 −2.0 0.0−0.2 −2.0 −6.7 Prob 0.590 0.005 0.863 0.735 0.104

FURTHER EMBODIMENTS OF THE INVENTION

This invention also is directed to methods for producing a maize plantby crossing a first parent maize plant with a second parent maize plantwherein either the first or second parent maize plant is Pioneer Brandhybrid 31G66. In one embodiment the parent hybrid maize plant 31G66 willbe crossed with another maize plant, sibbed, or selfed, to generate aninbred which may be used in the development of additional plants. Inanother embodiment, double haploid methods may be used to generate aninbred plant. Further, this invention is directed to methods forproducing a hybrid 31 G66-progeny maize plant by crossing hybrid maizeplant 31G66 with itself or a second maize plant and growing the progenyseed, and repeating the crossing and growing steps with the hybrid maize31G66-progeny plant from 1 to 2 times, 1 to 3 times, 1 to 4 times, or 1to 5 times. Thus, any such methods using the hybrid maize plant 31G66are part of this invention: selfing, sibbing, backcrosses, hybridproduction, crosses to populations, and the like.

All plants produced using hybrid maize plant 31G66 as a parent arewithin the scope of this invention, including plants derived from hybridmaize plant 31G66. This includes varieties essentially derived fromvariety 31G66 with the term “essentially derived variety” having themeaning ascribed to such term in 7 U.S.C. § 2104(a)(3) of the PlantVariety Protection Act, which definition is hereby incorporated byreference. This also includes progeny plant and parts thereof with atleast one ancestor that is hybrid maize plant 31 G66 and morespecifically where the pedigree of this progeny includes 1, 2, 3, 4,and/or 5 or cross pollinations to a maize plant 31G66, or a plant thathas 31G66 as a progenitor. All breeders of ordinary skill in the artmaintain pedigree records of their breeding programs. These pedigreerecords contain a detailed description of the breeding process,including a listing of all parental lines used in the breeding processand information on how such line was used. Thus, a breeder would know if31G66 were used in the development of a progeny line, and would alsoknow how many breeding crosses to a line other than 31 G66 were made inthe development of any progeny line. A progeny line so developed maythen be used in crosses with other, different, maize inbreds to producefirst generation (F₁) maize hybrid seeds and plants with superiorcharacteristics.

Specific methods and products produced using hybrid maize plant in plantbreeding are encompassed within the scope of the invention listed above.One such embodiment is the method of crossing hybrid maize plant 31G66with itself to form a homozygous inbred parent line. Hybrid 31G66 wouldbe sib or self pollinated to form a population of progeny plants. Thepopulation of progeny plants produced by this method is also anembodiment of the invention. This first population of progeny plantswill have received all of its alleles from hybrid maize plant 31G66. Theinbreeding process results in homozygous loci being generated and isrepeated until the plant is homozygous at substantially every loci andbecomes an inbred line. Once this is accomplished the inbred line may beused in crosses with other inbred lines, including but not limited toinbred parent lines disclosed herein to generate a first generation ofF1 hybrid plants. One of ordinary skill in the art can utilize breedernotebooks, or molecular methods to identify a particular hybrid plantproduced using an inbred line derived from maize hybrid plant 31G66, inaddition to comparing traits. Any such individual inbred plant is alsoencompassed by this invention.

These embodiments also include use of these methods with transgenic orbackcross conversions of maize hybrid plant 31 G66. Another suchembodiment is a method of developing a line genetically similar tohybrid maize plant 31G66 in breeding that involves the repeatedbackcrossing of an inbred parent of, or an inbred line derived from,hybrid maize plant 31G66 to another different maize plant any number oftimes. Using backcrossing methods, or even the tissue culture andtransgenic methods described herein, the backcross conversion methodsdescribed herein, or other breeding methods known to one of ordinaryskill in the art, one can develop individual plants, plant cells, andpopulations of plants that retain at least 25%, 30%, 35%, 40%, 45%, 50%,55%, 60%, 65%, 70%, 75%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 99.5%genetic similarity or identity to maize hybrid plant 31G66. Thepercentage of the genetics retained in the progeny may be measured byeither pedigree analysis or through the use of genetic techniques suchas molecular markers or electrophoresis. In pedigree analysis, onaverage 50% of the starting germplasm would be passed to the progenyline after one cross to a different line, 25% after another cross to adifferent line, and so on. Molecular markers could also be used toconfirm and/or determine the pedigree of the progeny line. The inbredparent would then be crossed to a second inbred parent of or derivedfrom hybrid maize plant 31G66 to create hybrid maize plant 31G66 withadditional beneficial traits such as transgenes or backcrossconversions.

One method for producing a line derived from hybrid maize plant is asfollows. One of ordinary skill in the art would obtain hybrid maizeplant 31G66 and cross it with another variety of maize, such as an eliteinbred variety. The F1 seed derived from this cross would be grown toform a population. The nuclear genome of the F1 would be made-up of 50%of hybrid maize plant 31 G66 and 50% of the other elite variety. The F1seed would be grown and allowed to self, thereby forming F2 seed. Onaverage the F2 seed nuclear genome would have derived 50% of its allelesfrom the parent hybrid plant 31G66 and 50% from the other maize variety,but various individual plants from the population would have a muchgreater percentage of their alleles derived from the parent maize hybridplant (Wang J. and R. Bernardo, 2000, Crop Sci. 40:659-665 and Bernardo,R. and A. L. Kahler, 2001, Theor. Appl. Genet 102:986-992). Molecularmarkers of 31G66, or its parents identified from routine screening ofthe deposited samples herein could be used to select and retain thoselines with high similarity to 31G66. The F2 seed would be grown andselection of plants would be made based on visual observation, markersand/or measurement of traits. The traits used for selection may be any31 G66 trait described in this specification, including the hybrid maizeplant 31G66 traits of high yield, above average husk coverage, aboveaverage root strength, above average tolerance to Gray Leaf Spot, aboveaverage tolerance to Northern Leaf Blight, excellent tolerance toFusarium Ear Rot, and particularly suited to the Southcentral,Southeast, Southwest, Eastern, and Western areas of the United States.

Such traits may also be the good general or specific combining abilityof 31G66, including its ability to produce backcross conversions, orother hybrids. The 31G66 progeny plants that exhibit one or more of thedesired 31G66 traits, such as those listed above, would be selected andeach plant would be harvested separately. This F3 seed from each plantwould be grown in individual rows and allowed to self. Then selectedrows or plants from the rows would be harvested individually. Theselections would again be based on visual observation, markers and/ormeasurements for desirable traits of the plants, such as one or more ofthe desirable 31G66 traits listed above.

The process of growing and selection would be repeated any number oftimes until a 31G66 progeny plant is obtained. The 31G66 progeny inbredplant would contain desirable traits in hybrid combination derived fromhybrid plant 31G66. The resulting progeny line would benefit from theefforts of the inventor(s), and would not have existed but for theinventor(s) work in creating 31G66. Another embodiment of the inventionis a 31G66 progeny plant that has received the desirable 31G66 traitslisted above through the use of 31G66, which traits were not exhibitedby other plants used in the breeding process.

The previous example can be modified in numerous ways, for instanceselection may or may not occur at every selfing generation, the hybridmay immediately be selfed without crossing to another plant, selectionmay occur before or after the actual self-pollination process occurs, orindividual selections may be made by harvesting individual ears, plants,rows or plots at any point during the breeding process described. Inaddition, double haploid breeding methods may be used at any step in theprocess. The population of plants produced at each and any cycle ofbreeding is also an embodiment of the invention. In each case the use of31G66 provides a substantial benefit. The linkage groups of 31G66 wouldbe retained in the progeny lines, and since current estimates of themaize genome size is about 50,000-80,000 genes (Xiaowu, Gai et al.,Nucleic Acids Research, 2000, Vol. 28, No. 1, 94-96), in addition to alarge amount of non-coding DNA that impacts gene expression, it providesa significant advantage to use 31G66 as starting material to produce aline that retains desired genetics or traits of 31 G66.

Another embodiment of this invention is the method of obtaining asubstantially homozygous 31G66 progeny plant by obtaining a seed fromthe cross of 31G66 and another maize plant and applying double haploidmethods to the F1 seed or F1 plant or to any successive filialgeneration. Such methods substantially decrease the number ofgenerations required to produce an inbred with similar genetics orcharacteristics to 31G66.

A further embodiment of the invention is a backcross conversion of 31G66obtained by crossing inbred parent plants of hybrid maize plant 31G66,which comprise the backcross conversion. For a dominant or additivetrait at least one of the inbred parents would include backcrossconversion in its genome. For a recessive trait, each parent wouldinclude the backcross conversion in its genome. In each case theresultant hybrid maize plant 31G66 obtained from the cross of theparents includes a backcross conversion or transgene. A backcrossconversion occurs when DNA sequences are introduced through traditional(non-transformation) breeding techniques, such as backcrossing (Hallaueret al., 1988). DNA sequences, whether naturally occurring or transgenes,may be introduced using these traditional breeding techniques. The termbackcross conversion is also referred to in the art as a single locusconversion. Reference is made to U.S. Pat. No. 2,002,10062506A1 for adetailed discussion of single locus conversions and traits that may beincorporated into 31G66 through backcross conversion.

Desired traits transferred through this process include, but are notlimited to, waxy starch, nutritional enhancements, industrialenhancements, disease resistance, insect resistance, herbicideresistance and yield enhancements. The trait of interest is transferredfrom the donor parent to the recurrent parent, in this case, an inbredparent of the maize plant disclosed herein. Backcross traits may resultfrom either the transfer of a dominant allele or a recessive allele.Selection of progeny containing the trait of interest is done by directselection for a trait associated with a dominant allele. Selection ofprogeny for a trait that is transferred via a recessive allele, such asthe waxy starch characteristic, requires growing and selfing the firstbackcross to determine which plants carry the recessive alleles.Recessive traits may require additional progeny testing in successivebackcross generations to determine the presence of the gene of interest.Along with selection for the trait of interest, progeny are selected forthe phenotype of the recurrent parent. It should be understood thatoccasionally additional polynucleotide sequences or genes aretransferred along with the backcross conversion trait of interest. Aprogeny comprising at least 95%, 96%, 97%, 98%, 99%, 99.5% and 99.9%genetic identity to the recurrent parent, the maize line disclosedherein, comprising the backcross conversion trait or traits of interest,is considered to be a backcross conversion of hybrid 31G66.

It should be understood that the plant can, through routine manipulationby detasseling, cytoplasmic genes, nuclear genes, or other factors, beproduced in a male-sterile form. The term manipulated to be male sterilerefers to the use of any available techniques to produce a male sterileversion of maize line 31G66. The male sterility may be either partial orcomplete male sterility.

Such embodiments are also within the scope of the present claims. Thisinvention includes hybrid maize seed of 31G66 and the hybrid maize plantproduced therefrom. The foregoing was set forth by way of example and isnot intended to limit the scope of the invention.

This invention is also directed to the use of hybrid maize plant 31G66in tissue culture. As used herein, the term plant includes plantprotoplasts, plant cell tissue cultures from which maize plants can beregenerated, plant calli, plant clumps, and plant cells that are intactin plants, or parts of plants, such as embryos, pollen, ovules, flowers,kernels, ears, cobs, leaves, seeds, husks, stalks, roots, root tips,anthers, silk and the like. As used herein the phrase “growing the seed”or “grown from the seed” includes embryo rescue, isolation of cells fromseed for use in tissue culture, as well as traditional growing methods.

Duncan, Williams, Zehr, and Widholm, Planta, (1985) 165:322-332 reflectsthat 97% of the plants cultured which produced callus were capable ofplant regeneration. Subsequent experiments with both inbreds and hybridsproduced 91% regenerable callus which produced plants. In a furtherstudy in 1988, Songstad, Duncan & Widholm in Plant Cell Reports (1988),7:262-265 reports several media additions which enhance regenerabilityof callus of two inbred lines. Other published reports also indicatedthat “nontraditional” tissues are capable of producing somaticembryogenesis and plant regeneration. K. P. Rao, et al., Maize GeneticsCooperation Newsletter, 60:64-65 (1986), refers to somatic embryogenesisfrom glume callus cultures and B. V. Conger, et al., Plant Cell Reports,6:345-347 (1987) indicates somatic embryogenesis from the tissuecultures of maize leaf segments. Thus, it is clear from the literaturethat the state of the art is such that these methods of obtaining plantsare, and were, “conventional” in the sense that they are routinely usedand have a very high rate of success.

Tissue culture of maize is described in European Patent Application,publication 160,390, incorporated herein by reference. Maize tissueculture procedures are also described in Green and Rhodes, “PlantRegeneration in Tissue Culture of Maize,” Maize for Biological Research(Plant Molecular Biology Association, Charlottesville, Virginia 1982, at367-372) and in Duncan, et al., “The Production of Callus Capable ofPlant Regeneration from Immature Embryos of Numerous Zea MaysGenotypes,” 165 Planta 322-332 (1985). Thus, another aspect of thisinvention is to provide cells which upon growth and differentiationproduce maize plants having the genotype and/or physiological andmorphological characteristics of hybrid maize plant 31G66.

The utility of hybrid maize plant 31G66 also extends to crosses withother species. Commonly, suitable species will be of the familyGraminaceae, and especially of the genera Zea, Tripsacum, Coix,Schlerachne, Polytoca, Chionachne, and Trilobachne, of the tribeMaydeae. Potentially suitable for crosses with 31G66 may be the variousvarieties of grain sorghum, Sorghum bicolor (L.) Moench.

Transformation of Maize

The advent of new molecular biological techniques have allowed theisolation and characterization of genetic elements with specificfunctions, such as encoding specific protein products. Scientists in thefield of plant biology developed a strong interest in engineering thegenome of plants to contain and express foreign genetic elements, oradditional, or modified versions of native or endogenous geneticelements in order to alter the traits of a plant in a specific manner.Any DNA sequence, whether from a different species or from the samespecies, that are inserted into the genome using transformation arereferred to herein collectively as “transgenes”. Over the last fifteento twenty years several methods for producing transgenic plants havebeen developed, and the present invention, in particular embodiments,also relates to transformed versions of the claimed hybrid maize plant31G66.

Numerous methods for plant transformation have been developed, includingbiological and physical, plant transformation protocols. See, forexample, Miki et al., “Procedures for Introducing Foreign DNA intoPlants” in Methods in Plant Molecular Biology and Biotechnology, Glick,B. R. and Thompson, J. E. Eds. (CRC Press, Inc., Boca Raton, 1993) pp.67-88 and Armstrong, “The First Decade of Maize Transformation: A Reviewand Future Perspective” (Maydica 44:101-109, 1999). In addition,expression vectors and in vitro culture methods for plant cell or tissuetransformation and regeneration of plants are available. See, forexample, Gruber et al., “Vectors for Plant Transformation” in Methods inPlant Molecular Biology and Biotechnology, Glick, B. R. and Thompson, J.E. Eds. (CRC Press, Inc., Boca Raton, 1993) pp. 89-119. See U.S. Pat.No. 6,118,055, which is herein incorporated by reference.

The most prevalent types of plant transformation involve theconstruction of an expression vector. Such a vector comprises a DNAsequence that contains a gene under the control of or operatively linkedto a regulatory element, for example a promoter. The vector may containone or more genes and one or more regulatory elements.

A genetic trait which has been engineered into a particular parent maizeplant using transformation techniques, could be moved into another lineusing traditional breeding techniques that are well known in the plantbreeding arts. These lines can then be crossed to generate a hybridmaize plant such as hybrid maize plant 31G66 which comprises atransgene. For example, a backcrossing approach could be used to move atransgene from a transformed maize plant to an elite inbred line and theresulting progeny would comprise a transgene. Also, if an inbred linewas used for the transformation then the transgenic plants could becrossed to a different inbred in order to produce a transgenic hybridmaize plant. As used herein, “crossing” can refer to a simple X by Ycross, or the process of backcrossing, depending on the context.

Various genetic elements can be introduced into the plant genome usingtransformation. These elements include but are not limited to genes;coding sequences; inducible, constitutive, and tissue specificpromoters; enhancing sequences; and signal and targeting sequences. SeeU.S. Pat. No. 6,284,953, which is herein incorporated by reference.

With transgenic plants according to the present invention, a foreignprotein can be produced in commercial quantities. Thus, techniques forthe selection and propagation of transformed plants, which are wellunderstood in the art, yield a plurality of transgenic plants which areharvested in a conventional manner, and a foreign protein then can beextracted from a tissue of interest or from total biomass. Proteinextraction from plant biomass can be accomplished by known methods whichare discussed, for example, by Heney and Orr, Anal. Biochem. 114: 92-6(1981). In one embodiment, the biomass of interest is seed.

A genetic map can be generated, primarily via conventional RestrictionFragment Length Polymorphisms (RFLP), Polymerase Chain Reaction (PCR)analysis, Simple Sequence Repeats (SSR) and Single NucleotidePolymorphisms (SNP) which identifies the approximate chromosomallocation of the integrated DNA molecule. For exemplary methodologies inthis regard, see Glick and Thompson, Methods In Plant Molecular BiologyAnd Biotechnology, pp. 269-284 (CRC Press, Boca Raton, 1993). Mapinformation concerning chromosomal location is useful for proprietaryprotection of a subject transgenic plant. If unauthorized propagation isundertaken and crosses made with other germplasm, the map of theintegration region can be compared to similar maps for suspect plants,to determine if the latter have a common parentage with the subjectplant. Map comparisons would involve hybridizations, RFLP, PCR, SSR andsequencing, all of which are conventional techniques.

Likewise, by means of the present invention, plants can be geneticallyengineered to express various phenotypes of agronomic interest. Throughthe transformation of maize the expression of genes can be modulated toenhance disease resistance, insect resistance, herbicide resistance,agronomic traits as well as grain quality traits. Transformation canalso be used to insert DNA sequences which control or help controlmale-sterility. DNA sequences native to maize as well as non-native DNAsequences can be transformed into maize and used to modulate levels ofnative or non-native proteins. Anti-sense technology, various promoters,targeting sequences, enhancing sequences, and other DNA sequences can beinserted into the maize genome for the purpose of modulating theexpression of proteins. Exemplary transgenes implicated in this regardinclude, but are not limited to, those categorized below.

-   1. Transgenes That Confer Resistance To Pests or Disease And That    Encode:

(A) Plant disease resistance genes. Plant defenses are often activatedby specific interaction between the product of a disease resistance gene(R) in the plant and the product of a corresponding avirulence (Avr)gene in the pathogen. A plant variety can be transformed with clonedresistance gene to engineer plants that are resistant to specificpathogen strains. See, for example, Jones et al., Science 266: 789(1994) (cloning of the tomato Cf-9 gene for resistance to Cladosporiumfulvum); Martin et al., Science 262: 1432 (1993) (tomato Pto gene forresistance to Pseudomonas syringae pv. tomato encodes a protein kinase);Mindrinos et al., Cell 78: 1089 (1994) (Arabidopsis RSP2 gene forresistance to Pseudomonas syringae).

(B) A Bacillus thuringiensis protein, a derivative thereof or asynthetic polypeptide modeled thereon. See, for example, Geiser et al.,Gene 48: 109 (1986), who disclose the cloning and nucleotide sequence ofa Bt δ-endotoxin gene. Moreover, DNA molecules encoding δ-endotoxingenes can be purchased from American Type Culture Collection (Rockville,Md.), for example, under ATCC Accession Nos. 40098, 67136, 31995 and31998. Other examples of Bacillus thuringiensis transgenes beinggenetically engineered are given in the following patents and hereby areincorporated by reference: U.S. Pat. Nos. 5,188,960; 5,689,052;5,880,275; and WO 97/40162.

(C) A lectin. See, for example, the disclosure by Van Damme et al.,Plant Molec. Biol. 24; 25 (1994), who disclose the nucleotide sequencesof several Clivia miniata mannose-binding lectin genes.

(D) A vitamin-binding protein such as avidin. See PCT ApplicationUS93/06487 the contents of which are hereby incorporated by reference.The application teaches the use of avidin and avidin homologues aslarvicides against insect pests.

(E) An enzyme inhibitor, for example, a protease inhibitor or an amylaseinhibitor. See, for example, Abe et al., J. Biol. Chem. 262: 16793(1987) (nucleotide sequence of rice cysteine proteinase inhibitor), Huubet al., Plant Molec. Biol. 21: 985 (1993) (nucleotide sequence of cDNAencoding tobacco proteinase inhibitor 1), and Sumitani et al., Biosci.Biotech. Biochem. 57: 1243 (1993) (nucleotide sequence of Streptomycesnitrosporeus α-amylase inhibitor) and U.S. Pat. No. 5,494,813.

(F) An insect-specific hormone or pheromone such as an ecdysteroid andjuvenile hormone, a variant thereof, a mimetic based thereon, or anantagonist or agonist thereof. See, for example, the disclosure byHammock et al., Nature 344: 458 (1990), of baculovirus expression ofcloned juvenile hormone esterase, an inactivator of juvenile hormone.

(G) An insect-specific peptide or neuropeptide which, upon expression,disrupts the physiology of the affected pest. For example, see thedisclosures of Regan, J. Biol. Chem. 269: 9 (1994) (expression cloningyields DNA coding for insect diuretic hormone receptor), and Pratt et.al., Biochem. Biophys. Res. Comm.163: 1243 (1989) (an allostatin isidentified in Diploptera puntata). See also U.S. Pat. No. 5,266,317 toTomalski et. al., who disclose genes encoding insect-specific, paralyticneurotoxins.

(H) An insect-specific venom produced in nature by a snake, a wasp, etc.For example, see Pang et al., Gene 116: 165 (1992), for disclosure ofheterologous expression in plants of a gene coding for a scorpioninsectotoxic peptide.

(I) An enzyme responsible for an hyperaccumulation of a monterpene, asesquiterpene, a steroid, hydroxamic acid, a phenylpropanoid derivativeor another non-protein molecule with insecticidal activity.

(J) An enzyme involved in the modification, including thepost-translational modification, of a biologically active molecule; forexample, a glycolytic enzyme, a proteolytic enzyme, a lipolytic enzyme,a nuclease, a cyclase, a transaminase, an esterase, a hydrolase, aphosphatase, a kinase, a phosphorylase, a polymerase, an elastase, achitinase and a glucanase, whether natural or synthetic. See PCTApplication WO 93/02197 in the name of Scott et al., which discloses thenucleotide sequence of a callase gene. DNA molecules which containchitinase-encoding sequences can be obtained, for example, from the ATCCunder Accession Nos. 39637 and 67152. See also Kramer et al, InsectBiochem. Molec. Biol. 23: 691 (1993), who teach the nucleotide sequenceof a cDNA encoding tobacco hookworm chitinase, and Kawalleck et al.,Plant Molec. Biol. 21: 673 (1993), who provide the nucleotide sequenceof the parsley ubi4-2 polyubiquitin gene.

(K) A molecule that stimulates signal transduction. For example, see thedisclosure by Botella et al., Plant Molec. Biol. 24: 757 (1994), ofnucleotide sequences for mung bean calmodulin cDNA clones, and Griess etal., Plant Physiol. 104: 1467 (1994), who provide the nucleotidesequence of a maize calmodulin cDNA clone.

(L) A hydrophobic moment peptide. See PCT Application WO 95/16776(disclosure of peptide derivatives of Tachyplesin which inhibit fungalplant pathogens) and PCT Application WO 95/18855 (teaches syntheticantimicrobial peptides that confer disease resistance), the respectivecontents of which are hereby incorporated by reference.

(M) A membrane permease, a channel former or a channel blocker. Forexample, see the disclosure by Jaynes et al., Plant Sci. 89: 43 (1993),of heterologous expression of a cecropin-βlytic peptide analog to rendertransgenic tobacco plants resistant to Pseudomonas solanacearum.

(N) A viral-invasive protein or a complex toxin derived therefrom. Forexample, the accumulation of viral coat proteins in transformed plantcells imparts resistance to viral infection and/or disease developmenteffected by the virus from which the coat protein gene is derived, aswell as by related viruses. See Beachy et al., Ann. Rev. Phytopathol.28: 451 (1990). Coat protein-mediated resistance has been conferred upontransformed plants against alfalfa mosaic virus, cucumber mosaic virus,tobacco streak virus, potato virus X, potato virus Y, tobacco etchvirus, tobacco rattle virus and tobacco mosaic virus. Id.

(O) An insect-specific antibody or an immunotoxin derived therefrom.Thus, an antibody targeted to a critical metabolic function in theinsect gut would inactivate an affected enzyme, killing the insect. CfTaylor et al., Abstract #497, SEVENTH INT'L SYMPOSIUM ON MOLECULARPLANT-MICROBE INTERACTIONS (Edinburgh, Scotland, 1994) (enzymaticinactivation in transgenic tobacco via production of single-chainantibody fragments).

(P) A virus-specific antibody. See, for example, Tavladoraki et al.,Nature 366: 469 (1993), who show that transgenic plants expressingrecombinant antibody genes are protected from virus attack.

(Q) A developmental-arrestive protein produced in nature by a pathogenor a parasite. Thus, fungal endo α-1,4-D-polygalacturonases facilitatefungal colonization and plant nutrient release by solubilizing plantcell wall homo-α-1,4-D-galacturonase. See Lamb et al., Bio/Technology10: 1436 (1992). The cloning and characterization of a gene whichencodes a bean endopolygalacturonase-inhibiting protein is described byToubart et al., Plant J. 2: 367 (1992).

(R) A developmental-arrestive protein produced in nature by a plant. Forexample, Logemann et al., Bio/Technology 10: 305 (1992), have shown thattransgenic plants expressing the barley ribosome-inactivating gene havean increased resistance to fungal disease.

(S) Genes involved in the Systemic Acquired Resistance (SAR) Responseand/or the pathogenesis related genes. Briggs, S., Current Biology, 5(2)(1995).

(T) Antifungal genes (Cornelissen and Melchers, PI. Physiol.101:709-712, (1993) and Parijs et al., Planta 183:258-264, (1991) andBushnell et al., Can. J. of Plant Path. 20(2):137-149 (1998).

2. Transgenes that Confer Resistance to a Herbicide, for Example:

(A) A herbicide that inhibits the growing point or meristem, such as animidazalinone or a sulfonylurea. Exemplary genes in this category codefor mutant ALS and AHAS enzyme as described, for example, by Lee et al.,EMBO J. 7: 1241 (1988), and Miki et al., Theor Appl. Genet. 80: 449(1990), respectively. See also, U.S. Pat. Nos. 5,605,011; 5,013,659;5,141,870; 5,767,361; 5,731,180; 5,304,732; 4,761,373; 5,331,107;5,928,937; and 5,378,824; and international publication WO 96/33270,which are incorporated herein by reference in their entireties for allpurposes.

(B) Glyphosate (resistance imparted by mutant5-enolpyruvl-3-phosphikimate synthase (EPSP), and aroA genes,respectively) and other phosphono compounds such as glufosinate(phosphinothricin acetyl transferase (PAT) and Streptomyceshygroscopicus phosphinothricin acetyl transferase (bar) genes), andpyridinoxy or phenoxy proprionic acids and cycloshexones (ACCaseinhibitor-encoding genes). See, for example, U.S. Pat. No. 4,940,835 toShah et al., which discloses the nucleotide sequence of a form of EPSPSwhich can confer glyphosate resistance. U.S. Pat. No. 5,627,061 to Barryet al. also describes genes encoding EPSPS enzymes. See also U.S. Pat.Nos. 6,248,876 B1; 6,040,497; 5,804,425; 5,633,435; 5,145,783;4,971,908; 5,312,910; 5,188,642; 4,940,835; 5,866,775; 6,225,114 B1;6,130,366; 5,310,667; 4,535,060; 4,769,061; 5,633,448; 5,510,471; Re.36,449; RE 37,287 E; and 5,491,288; and international publications WO97/04103; WO 97/04114; WO 00/66746; WO 01/66704; WO 00/66747 and WO00/66748, which are incorporated herein by reference in their entirety.Glyphosate resistance is also imparted to plants that express a genethat encodes a glyphosate oxido-reductase enzyme as described more fullyin U.S. Pat. Nos. 5,776,760 and 5,463,175, which are incorporated hereinby reference in their entirety. In addition glyphosate resistance can beimparted to plants by the over expression of genes encoding glyphosateN-acetyltransferase. See, for example, U.S. Application Ser. Nos.60/244,385; 601377,175 and 601377,719.

A DNA molecule encoding a mutant aroA gene can be obtained under ATCCAccession No. 39256, and the nucleotide sequence of the mutant gene isdisclosed in U.S. Pat. No. 4,769,061 to Comai. European PatentApplication No. 0 333 033 to Kumada et al., and U.S. Pat. No. 4,975,374to Goodman et al disclose nucleotide sequences of glutamine synthetasegenes which confer resistance to herbicides such as L-phosphinothricin.The nucleotide sequence of a phosphinothricin-acetyl-transferase gene isprovided in European Patent No. 0 242 246 and 0 242 236 to Leemans etal. De Greef et al., Bio/Technology 7: 61 (1989), describe theproduction of transgenic plants that express chimeric bar genes codingfor phosphinothricin acetyl transferase activity. See also, U.S. Pat.Nos. 5,969,213; 5,489,520; 5,550,318; 5,874,265; 5,919,675; 5,561,236;5,648,477; 5,646,024; 6,177,616 B1; and 5,879,903, which areincorporated herein by reference in their entirety. Exemplary of genesconferring resistance to phenoxy proprionic acids and cycloshexones,such as sethoxydim and haloxyfop, are the Acc1-S1, Acc1-S2 and Acc1-S3genes described by Marshall et al., Theor Appl Genet. 83: 435 (1992).

(C) A herbicide that inhibits photosynthesis, such as a triazine (psbAand gs+genes) and a benzonitrile (nitrilase gene). Przibilla et al.,Plant Cell 3: 169 (1991), describe the transformation of Chlamydomonaswith plasmids encoding mutant psbA genes. Nucleotide sequences fornitrilase genes are disclosed in U.S. Pat. No. 4,810,648 to Stalker, andDNA molecules containing these genes are available under ATCC AccessionNos. 53435, 67441 and 67442. Cloning and expression of DNA coding for aglutathione S-transferase is described by Hayes et al, Biochem. J. 285:173 (1992).

(D) Acetohydroxy acid synthase, which has been found to make plants thatexpress this enzyme resistant to multiple types of herbicides, has beenintroduced into a variety of plants (see, e.g., Hattori et al. (1995)Mol Gen Genet 246:419). Other genes that confer tolerance to herbicidesinclude: a gene encoding a chimeric protein of rat cytochrome P4507A1and yeast NADPH-cytochrome P450 oxidoreductase (Shiota et al. (1994)Plant Physiol. 106(1):17-23), genes for glutathione reductase andsuperoxide dismutase (Aono et al. (1995) Plant Cell Physiol 36:1687, andgenes for various phosphotransferases (Datta et al. (1992) Plant MolBiol 20:619).

(E) Protoporphyrinogen oxidase (protox) is necessary for the productionof chlorophyll, which is necessary for all plant survival. The protoxenzyme serves as the target for a variety of herbicidal compounds. Theseherbicides also inhibit growth of all the different species of plantspresent, causing their total destruction. The development of plantscontaining altered protox activity which are resistant to theseherbicides are described in U.S. Pat. Nos. 6,288,306 B1; 6,282,837 B1;and 5,767,373; and international publication WO 01/12825, which areincorporated herein by reference in their entireties of all purposes.

3. Transgenes that Confer or Contribute to a Grain Trait, Such as:

(A) Modified fatty acid metabolism, for example, by transforming a plantwith an antisense gene of stearyl ACP desaturase to increase stearicacid content of the plant. See Knultzon et al., Proc. Natl. Acad. Sci.USA 89: 2624 (1992).

(B) Decreased phytate content

-   -   (1) Introduction of a phytase-encoding gene would enhance        breakdown of phytate, adding more free phosphate to the        transformed plant. For example, see Van Hartingsveldt et al.,        Gene 127: 87 (1993), for a disclosure of the nucleotide sequence        of an Aspergillus niger phytase gene.    -   (2) A gene could be introduced that reduces phytate content. In        maize, this, for example, could be accomplished, by cloning and        then re-introducing DNA associated with the single allele which        is responsible for maize mutants characterized by low levels of        phytic acid. See Raboy et al., Maydica 35: 383 (1990).

(C) Modified carbohydrate composition effected, for example, bytransforming plants with a gene coding for an enzyme that alters thebranching pattern of starch. See Shiroza et al., J. Bacteriol. 170: 810(1988) (nucleotide sequence of Streptococcus mutans fructosyltransferasegene), Steinmetz et al., Mol. Gen. Genet. 200: 220 (1985) (nucleotidesequence of Bacillus subtilis levansucrase gene), Pen et al.,Bio/Technology 10: 292 (1992) (production of transgenic plants thatexpress Bacillus licheniformis α-amylase), Elliot et al., Plant Molec.Biol. 21: 515 (1993) (nucleotide sequences of tomato invertase genes),Søgaard et al., J. Biol. Chem. 268: 22480 (1993) (site-directedmutagenesis of barley α-amylase gene), and Fisher et al., Plant Physiol.102: 1045 (1993) (maize endosperm starch branching enzyme II).

(D) Elevated oleic acid via FAD-2 gene modification and/or decreasedlinolenic acid via FAD-3 gene modification (see U.S. Pat. Nos.6,063,947; 6,323,392; and WO 93/11245).

4. Genes that Control Male-sterility:

(A) Introduction of a deacetylase gene under the control of atapetum-specific promoter and with the application of the chemicalN-Ac-PPT (WO 0/129237).

(B) Introduction of various stamen-specific promoters (WO 92/13956, WO92/13957).

(C) Introduction of the barnase and the barstar gene (Paul et al. PlantMol. Biol. 19:611-622, 1992).

Genetic Marker Profile Through SSR

The present invention comprises a hybrid corn plant which ischaracterized by the molecular and physiological data presented hereinand in the representative sample of said hybrid and of the inbredparents of said hybrid deposited with the ATCC.

To select and develop a superior hybrid, it is necessary to identify andselect genetically unique individuals that occur in a segregatingpopulation. The segregating population is the result of a combination ofcrossover events plus the independent assortment of specificcombinations of alleles at many gene loci that results in specific andunique genotypes. Once such a line is developed its value to society issubstantial since it is important to advance the germplasm base as awhole in order to maintain or improve traits such as yield, diseaseresistance, pest resistance and plant performance in extreme weatherconditions. Backcross trait conversions are routinely used to add ormodify one or a few traits of such a line and this further enhances itsvalue and usefulness to society. The genetic variation among individualprogeny of a breeding cross allows for the identification of rare andvaluable new genotypes. Once identified, it is possible to utilizeroutine and predictable breeding methods to develop progeny that retainthe rare and valuable new genotypes developed by the initial breeder.

Phenotypic traits exhibited by 31G66 can be used to characterize thegenetic contribution of 31G66 to progeny lines developed through the useof 31G66. Quantitative traits including, but not limited to, yield,maturity, stay green, root lodging, stalk lodging, and early growth aretypically governed by multiple genes at multiple loci. 31G66 progenyplants that retain the same degree of phenotypic expression of thesequantitative traits as 31G66 have received significant genotypic andphenotypic contribution from 31G66. This characterization is enhancedwhen such quantitative trait is not exhibited in non-31G66 breedingmaterial used to develop the 31G66 progeny.

As discussed, supra, in addition to phenotypic observations, a plant canalso be described by its genotype. The genotype of a plant can bedescribed through a genetic marker profile which can identify plants ofthe same variety, a related variety or be used to determine or validatea pedigree. Genetic marker profiles can be obtained by techniques suchas Restriction Fragment Length Polymorphisms (RFLPs), Randomly AmplifiedPolymorphic DNAs (RAPDs), Arbitrarily Primed Polymerase Chain Reaction(AP-PCR), DNA Amplification Fingerprinting (DAF), Sequence CharacterizedAmplified Regions (SCARs), Amplified Fragment Length Polymorphisms(AFLPs), Simple Sequence Repeats (SSRs) which are also referred to asMicrosatellites, and Single Nucleotide Polymorphisms (SNPs). Forexample, see Berry, Don, et al., “Assessing Probability of AncestryUsing Simple Sequence Repeat Profiles: Applications to Maize Hybrids andInbreds”, Genetics, 2002, 161:813-824, which is incorporated byreference herein in its entirety.

Particular markers used for these purposes are not limited to the set ofmarkers disclosed herewithin, but are envisioned to include any type ofmarker and marker profile which provides a means of distinguishingvarieties. In addition to being used for identification of inbredparents, hybrid variety 31G66, a hybrid produced through the use of31G66 or its parents, and the identification or verification of pedigreefor progeny plants produced through the use of 31G66, the genetic markerprofile is also useful in breeding and developing backcross conversions.

Means of performing genetic marker profiles using SSR polymorphisms arewell known in the art. SSRs are genetic markers based on polymorphismsin repeated nucleotide sequences, such as microsatellites. A markersystem based on SSRs can be highly informative in linkage analysisrelative to other marker systems in that multiple alleles may bepresent. Another advantage of this type of marker is that, through useof flanking primers, detection of SSRs can be achieved, for example, bythe polymerase chain reaction (PCR), thereby eliminating the need forlabor-intensive Southern hybridization. The PCR™ detection is done byuse of two oligonucleotide primers flanking the polymorphic segment ofrepetitive DNA. Repeated cycles of heat denaturation of the DNA followedby annealing of the primers to their complementary sequences at lowtemperatures, and extension of the annealed primers with DNA polymerase,comprise the major part of the methodology.

Following amplification, markers can be scored by gel electrophoresis ofthe amplification products. Scoring of marker genotype is based on thesize of the amplified fragment as measured by molecular weight (MW)rounded to the nearest integer. While variation in the primer used or inlaboratory procedures can affect the reported molecular weight, relativevalues should remain constant regardless of the specific primer orlaboratory used. When comparing lines it is preferable if all SSRprofiles are performed in the same lab. An SSR service is available tothe public on a contractual basis by Paragen, Research Triangle Park,North Carolina (formerly Celera AgGen of Davis, California).

Primers used for the SSRs suggested herein are publicly available andmay be found in the Maize GDB using the World Wide Web prefix followedby maizegdb.org (maintained by the USDA Agricultural Research Service),in Sharopova et al. (Plant Mol. Biol. 48(5-6):463-481), Lee et al.(Plant Mol. Biol. 48(5-6); 453-461). Some marker information may beavailable from Paragen.

Map information is provided in centimorgans (cM) and based on acomposite map developed by Pioneer Hi-Bred. This composite map wascreated by identifying common markers between various maps and usinglinear regression to place the intermediate markers. The reference mapused was UMC98. Map positions for the SSR markers reported herein willvary depending on the mapping population used. Any chromosome numbersreported in parenthesis represent other chromosome locations for suchmarker that have been reported in the literature or on the Maize GDB.Map positions are available on the Maize GDB for a variety of differentmapping populations.

TABLE 3 SSR Markers Locus Chrom# Bin # bnlg439 1  1.03 bnlg619 9  9.07bnlg653 5  5.04 bnlg1137 4  4.06 umc1037 9  9.02 dupssr26 1  1.04phi100175 8  8.03 phi101049 2  2.10 phi102228 3  3.06 phi104127 3  3.01phi108411 9  9.05 phi109188 5  5.03 phi109275 1  1.03 phi109642 2  2.03phi159819 6  6.00(6.08) phi193225 3  3.02 phi213984 4  4.01 phi227562 1 1.11 phi233376 8  8.09 phi236654 9  9.05 phi251315 2  2.07 phi260485 1 1.11 phi265454 1  1.11 phi295450 4  4.01 phi299852 6  6.07 phi301654 1010.04 umc2038 4  4.07 phi308090 4  4.04 phi308707 1  1.10 phi323065 1 1.08 phi323152 10 10.05 phi328175 7  7.04 phi328189 2  2.08 phi330507 5 5.04 phi331888 5  5.04 phi333597 5  5.05 phi335539 1  1.08 phi338882 6.XX phi339017 1  1.03 phi364545 6  6.07 phi374118 3  3.02 phi389203 6 6.03 phi396160 5  5.02 umc1463 6  6.06 phi402893 2  2.00 phi404206 3 3.01 phi420701 8  8.00 phi423298 1  1.08 phi423796 6  6.01 phi427434 2 2.08 phi427913 1  1.01 phi435417 2  2.08 phi438301 4  4.05 phi445613 6 6.05 phi448880 9  9.06(9.07) phi452693 6  6.04 phi453121 3  3.00umc1159 7  7.01 umc1413 6  6.05 phi96100 2  2.01 phi96342 10 10.02bnlg1016 1  1.04 bnlg1017 2  2.02 bnlg1018 2  2.04 bnlg1035 3  3.05bnlg1056 8  8.08 bnlg1057 1  1.06 bnlg1064 2  2.03 bnlg1065 8  8.07bnlg1007 1  1.02 bnlg1012 9  9.04 bnlg1014 1  1.01 bnlg1019 3  3.04bnlg1028 10 10.06 bnlg1036 2  2.06 bnlg1037 10 10.03 bnlg1041 1  1.06bnlg1070 7  7.03 bnlg1074 10 10.05 bnlg1079 10 10.03 bnlg1083 1  1.02bnlg1094 7  7.02 bnlg1113 3  3.04 bnlg1118 5  5.07 bnlg1127 1  1.02bnlg1130 1  1.XX bnlg1138 2  2.06 bnlg1141 2  2.08 bnlg1144 3  3.02bnlg1152 8  8.06 bnlg1159 9  9.04 bnlg1160 3  3.06 bnlg1162 4  4.03bnlg1174 6  6.05 bnlg1176 8  8.05 bnlg1185 10 10.07 bnlg1189 4  4.07bnlg1194 8  8.02 bnlg1203 1  1.03 bnlg1208 5  5.04 bnlg1292 7  7.03bnlg1331 1  1.09 bnlg1346 5  5.07 bnlg1484 1  1.03 bnlg1638 3  3.04bnlg1690 2  2.XX bnlg1720 1  1.09(1.10) bnlg1740 6  6.07 bnlg1755 4 4.05 bnlg1759 6  6.07 bnlg1784 4  4.07 bnlg1810 9  9.01 bnlg1832 1 1.05 bnlg1863 8  8.03 bnlg1890 4  4.11 bnlg1892 5  5.04 bnlg1909 2 2.05 bnlg1937 4  4.05(4.06) bnlg1452 3  3.04 bnlg1940 2  2.08 bnlg19513  3.06 bnlg1953 1  1.02 bnlg2031 1  1.XX bnlg2046 8  8.04 bnlg2082 8 8.03 bnlg2086 1  1.04 bnlg2122 9  9.01 bnlg2132 7  7.00 bnlg2228 1 1.08 bnlg2237 2  2.08 bnlg2238 1  1.04 bnlg2241 3  3.06 bnlg2244 4 4.08 bnlg2271 7  7.03 bnlg2277 2  2.02 bnlg1597 1  1.09(1.10) bnlg16473  3.02 bnlg1655 10 10.03 bnlg1006 5  5.00 bnlg1031 8  8.06 bnlg1129 9 9.08 bnlg1258 2  2.08 bnlg1265 4  4.05 bnlg1327 2  2.02 bnlg1375 9 9.07 bnlg1396 2  2.06 bnlg1422 6  6.01 bnlg1429 1  1.02 bnlg1450 1010.07 bnlg1496 3  3.09 bnlg1520 2  2.09 bnlg1523 3  3.03 bnlg1537 2 2.03 bnlg1556 1  1.07 bnlg1565 4  4.09 bnlg1597 5  5.08 bnlg1615 1 1.06 bnlg1627 1  1.02 bnlg1655 10 10.03 bnlg1711 5  5.07 bnlg1816 3 3.04 bnlg1828 8  8.07 bnlg1831 2  2.06 bnlg1839 10 10.07 bnlg1884 1 1.05 bnlg1886 1  1.05 bnlg2323 5  5.04 phi002 1  1.08 phi011 1  1.09phi015 8  8.08 phi021 4  4.03 phi026 4  4.05 phi029 3  3.04 phi032 9 9.04 phi033 9  9.01 phi034 7  7.02 phi041 10 10.00 phi050 10 10.03phi051 7  7.05 phi053 3  3.05 phi056 1  1.01 phi059 10 10.02 phi062 1010.04 phi064 1  1.11 phi069 7  7.05 phi070 6  6.07 phi072 4  4.00(4.01)phi073 3  3.05 phi076 4  4.11 phi079 4  4.05 phi083 2  2.04 phi085 5 5.06 phi090 2  2.08 phi093 4  4.08 phi096 4  4.04 phi115 8  8.03 phi1167  7.06 phi121 8  8.03 phi127 2  2.08 umc1006 6  6.02 umc1229 6  6.01umc1498 6  6.01 umc1517 6  6.01 umc1572 6  6.02 umc1656 6  6.02 umc18836  6.00 umc2055 6  6.04(6.05)

A genetic marker profile of a hybrid should be the sum of its inbredparents, e.g., if one inbred parent had the allele 168 (base pairs) at aparticular locus, and the other inbred parent had 172 the hybrid is168.172 (heterozygous) by inference. Subsequent generations of progenyproduced by selection and breeding are expected to be of genotype 168(homozygous), 172 (homozygous), or 168.172 for that locus position. Whenthe F1 plant is used to produce an inbred, the locus should be either168 or 172 for that position.

In addition, plants and plant parts substantially benefiting from theuse of 31G66 in their development such as 31G66 comprising a backcrossconversion, transgene, or genetic sterility factor, may be identified byhaving a molecular marker profile with a high percent identity to 31G66.Such a percent identity might be 95%, 96%, 97%, 98%, 99%, 99.5% or 99.9%identical to 31G66.

The SSR profile of 31G66 also can be used to identify essentiallyderived varieties and other progeny lines developed from the use of31G66, as well as cells and other plant parts thereof. Progeny plantsand plant parts produced using 31G66 may be identified by having amolecular marker profile of at least 25%, 30%, 35%, 40%, 45%, 50%, 55%,60%, 65%, 70%, 75%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 99.5% geneticcontribution from hybrid maize plant 31G66.

INDUSTRIAL APPLICABILITY

Maize is used as human food, livestock feed, and as raw material inindustry. The food uses of maize, in addition to human consumption ofmaize kernels, include both products of dry- and wet-milling industries.The principal products of maize dry milling are grits, meal and flour.The maize wet-milling industry can provide maize starch, maize syrups,and dextrose for food use. Maize oil is recovered from maize germ, whichis a by-product of both dry- and wet-milling industries.

Maize, including both grain and non-grain portions of the plant, is alsoused extensively as livestock feed, primarily for beef cattle, dairycattle, hogs, and poultry.

Industrial uses of maize include production of ethanol, maize starch inthe wet-milling industry and maize flour in the dry-milling industry.The industrial applications of maize starch and flour are based onfunctional properties, such as viscosity, film formation, adhesiveproperties, and ability to suspend particles. The maize starch and flourhave application in the paper and textile industries. Other industrialuses include applications in adhesives, building materials, foundrybinders, laundry starches, explosives, oil-well muds, and other miningapplications.

Plant parts other than the grain of maize are also used in industry: forexample, stalks and husks are made into paper and wallboard and cobs areused for fuel and to make charcoal.

The seed of the hybrid maize plant, the plant produced from the seed, aplant produced from crossing of maize hybrid plant 31G66 and variousparts of the hybrid maize plant and transgenic versions of theforegoing, can be utilized for human food, livestock feed, and as a rawmaterial in industry.

DEPOSITS

Applicant has made a deposit of at least 2500 seeds of hybrid maizeplant 31G66 and inbred parent plants GE587257 and GE565923 with theAmerican Type Culture Collection (ATCC), Manassas, Va. 20110 USA, ATCCDeposit Nos. PTA-6490, PTA-6465, and PTA-6463, respectively. The seedsdeposited with the ATCC on Dec. 28, 2004, Dec. 17, 2004, and Dec. 17,2004, respectively were taken from the deposit maintained by PioneerHi-Bred International, Inc., 800 Capital Square, 400 Locust Street, DesMoines, Iowa 50309-2340, since prior to the filing date of thisapplication. Access to this deposit will be available during thependency of the application to the Commissioner of Patents andTrademarks and persons determined by the Commissioner to be entitledthereto upon request. Upon allowance of any claims in the application,the Applicant will make available to the public, pursuant to 37 C.F.R.1.808, a deposit of at least 2500 seeds of hybrid maize plant 31G66 andinbred parent plants GE587257 and GE565923 with the American TypeCulture Collection (ATCC), 10801 University Boulevard, Manassas, VA20110-2209. This deposit of seed of hybrid maize plant 31G66 and inbredparent plants GE587257 and GE565923 will be maintained in the ATCCdepository, which is a public depository, for a period of 30 years, or 5years after the most recent request, or for the enforceable life of thepatent, whichever is longer, and will be replaced if it becomesnonviable during that period. Additionally, Applicant has satisfied allthe requirements of 37 C.F.R. §§1.801-1.809, including providing anindication of the viability of the sample upon deposit. Applicant has noauthority to waive any restrictions imposed by law on the transfer ofbiological material or its tranportaion in commerce. Applicant does notwaive may infringement of its rights granted under this patent or underthe Plant Variety Protection Act (7 USC 2321 et seq.).

All publications, patents and patent applications mentioned in thespecification are indicative of the level of those skilled in the art towhich this invention pertains. All such publications, patents and patentapplications are incorporated by reference herein to the same extent asif each was specifically and individually indicated to be incorporatedby reference herein.

The foregoing invention has been described in detail by way ofillustration and example for purposes of clarity and understanding.However, it will be obvious that certain changes and modifications suchas backcross conversions and mutations, somoclonal variants, variantindividuals selected from large populations of the plants of the instantinbred and the like may be practiced within the scope of the invention,as limited only by the scope of the appended claims.

1. A Seed of hybrid maize variety designated 31G66, representative seedof said variety having been deposited under ATCC Accession No. PTA-6490.2. A maize plant, or a part thereof, produced by growing the seed ofclaim
 1. 3. Pollen of the plant of claim
 2. 4. An ovule of the plant ofclaim
 2. 5. A tissue culture of regenerable cells produced from theplant of claim
 2. 6. A protoplast produced from the tissue culture ofclaim
 5. 7. The tissue culture of claim 5, wherein cells of the tissueculture are produced from a tissue selected from the group consisting ofleaf, pollen, embryo, root, root tip, anther, silk, flower, kernel, ear,cob, husk and stalk.
 8. A maize plant regenerated from the tissueculture of claim 5, said plant having all the morphological andphysiological characteristics of hybrid maize plant 31G66,representative seed of said hybrid maize plant having been depositedunder ATCC Accession No. PTA-6490.
 9. A method for producing an F1hybrid maize seed, comprising crossing the plant of claim 2 with adifferent maize plant and harvesting the resultant F1 hybrid maize seed.10. A maize plant, or a part thereof, having all the physiological andmorphological characteristics of the hybrid maize plant 31G66,representative seed of said hybrid maize plant having been depositedunder ATCC Accession No. PTA-6490.
 11. A method of introducing a desiredtrait into a hybrid maize variety 31G66 comprising: (a) crossing atleast one of inbred maize parent plants GE587257 and GE565923,representative samples of which have been deposited under ATCC AccessionNos. as PTA-6465 and PTA-6463 respectively, with another maize line thatcomprises a desired trait, to produce F1 progeny plants, wherein thedesired trait is selected from the group consisting of male sterility,herbicide resistance, insect resistance, disease resistance and waxystarch; (b) selecting said F1 progeny plants that have the desired traitto produce selected F1 progeny plants; (c) backcrossing the selectedprogeny plants with said inbred maize parent plant to produce backcrossprogeny plants; (d) selecting for backcross progeny plants that have thedesired trait and morphological and physiological characteristics ofsaid inbred maize parent plant; (e) repeating steps (c) and (d) three ormore times in succession to produce selected fourth or higher backcrossprogeny plants; and (f) crossing said fourth or higher backcross progenyplant with the other inbred maize parent plant to generate a hybridmaize variety 31G66 with the desired trait and all of the morphologicaland physiological characteristics of hybrid maize variety 31G66 listedin Table 1 as determined at the 5% significance level when grown in thesame environmental conditions.
 12. A plant produced by the method ofclaim 11, wherein the plant has the desired trait and all of thephysiological and morphological characteristics of hybrid maize variety31G66 listed in Table 1 as determined at the 5% significance level whengrown in the same environmental conditions.
 13. The plant of claim 12wherein the desired trait is herbicide resistance and the resistance isconferred to an herbicide selected from the group consisting ofimidazolinone, sulfonylurea, glyphosate, glufosinate,L-phosphinothricin, triazine and benzonitrile.
 14. The plant of claim 12wherein the desired trait is insect resistance and the insect resistanceis conferred by a transgene encoding a Bacillus thuringiensis endotoxin.15. The plant of claim 12 wherein the desired trait is male sterilityand the trait is conferred by a cytoplasmic nucleic acid molecule thatconfers male sterility.
 16. A method of modifying fatty acid metabolism,phytic acid metabolism or carbohydrate metabolism in a hybrid maizevariety 31G66 comprising: (a) crossing at least one of inbred maizeparent plants GE587257 and GE565923, representative samples of whichhave been deposited under ATCC Accession Nos. PTA-6465 and PTA-6463respectively, with another maize line that comprise a nucleic acidmolecule encoding an enzyme selected from the group consisting ofphytase, fructosyltransferase, levansucrase, alpha-amylase, invertaseand starch branching enzyme or encoding an antisense of stearyl-ACPdesaturase; (b) selecting said F1 progeny plants that have said nucleicacid molecule to produce selected F1 progeny plants; (c) backcrossingthe selected progeny plants with said inbred maize parent plant toproduce backcross progeny plants; (d) selecting for backcross progenyplants that have said nucleic acid molecule and morphological andphysiological characteristics of said inbred maize parent plant; (e)repeating steps (c) and (d) three or more times in succession to produceselected fourth or higher backcross progeny plants; and (f) crossingsaid fourth or higher backcross progeny plant with the other inbredmaize parent plant to generate a hybrid maize variety 31 G66 thatcomprises said nucleic acid molecule and has all of the morphologicaland physiological characteristics of hybrid maize variety 31G66 listedin Table 1 as determined at the 5% significance level when grown in thesame environmental conditions.
 17. A plant produced by the method ofclaim 16, wherein the plant comprises the nucleic acid molecule and hasall of the physiological and morphological characteristics of hybridmaize variety 31G66 listed in Table 1 as determined at the 5%significance level when grown in the same environmental conditions. 18.A method for producing a maize seed, comprising crossing the plant ofclaim 2 with itself or a different maize plant and harvesting theresultant maize seed.